diff options
| author | Laurent Balland-Poirier <laurent.balland-poirier@laposte.net> | 2016-08-18 19:13:06 +0200 |
|---|---|---|
| committer | Olivier Hallot <ohallot@collabora.co.uk> | 2016-08-29 21:28:12 +0000 |
| commit | a1ae3364bcbf664a39922cefc081ccc74fce570c (patch) | |
| tree | f5cc999c3a764772d7779bcaa8d5c5f65e3bcffe /source/text/schart | |
| parent | 32e04637f0cdf7f44b17c83fb78f66752430ab41 (diff) | |
Rewrite Trend Line Help page
Insert new types of regression
Update constraints
Add new options (X-Y names)
Reorganisation of the page
Update:
Convert all power value to <sup></sup>
Convert unicode character sigma to its HTML code Σ
as Σ is not recognized
Change-Id: If1fe158d8c19ac80fb03ef3c7491ada5b666ccd0
Reviewed-on: https://gerrit.libreoffice.org/28225
Reviewed-by: Olivier Hallot <ohallot@collabora.co.uk>
Tested-by: Olivier Hallot <ohallot@collabora.co.uk>
Diffstat (limited to 'source/text/schart')
| -rw-r--r-- | source/text/schart/01/04050100.xhp | 316 |
1 files changed, 207 insertions, 109 deletions
diff --git a/source/text/schart/01/04050100.xhp b/source/text/schart/01/04050100.xhp index fe9a516bae..367cf541f7 100644 --- a/source/text/schart/01/04050100.xhp +++ b/source/text/schart/01/04050100.xhp @@ -1,6 +1,5 @@ <?xml version="1.0" encoding="UTF-8"?> <helpdocument version="1.0"> - <!-- * This file is part of the LibreOffice project. * @@ -17,121 +16,220 @@ * License, Version 2.0 (the "License"); you may not use this file * except in compliance with the License. You may obtain a copy of * the License at http://www.apache.org/licenses/LICENSE-2.0 . - --> - +--> <meta> - <topic id="textschart0104050100xml" indexer="include" status="PUBLISH"> - <title xml-lang="en-US" id="tit">Trend Lines </title> - <filename>/text/schart/01/04050100.xhp</filename> - </topic> - </meta> - <body> -<bookmark xml-lang="en-US" branch="index" id="bm_id1744743"><bookmark_value>calculating;regression curves</bookmark_value> - <bookmark_value>regression curves in charts</bookmark_value> - <bookmark_value>trend lines in charts</bookmark_value> - <bookmark_value>mean value lines in charts</bookmark_value> + <topic id="textschart0104050100xml" indexer="include" status="PUBLISH"> + <title id="tit" xml-lang="en-US">Trend Lines</title> + <filename>/text/schart/01/04050100.xhp</filename> + </topic> +</meta> + +<body> + +<bookmark xml-lang="en-US" branch="index" id="bm_id1744743"> + <bookmark_value>calculating;regression curves</bookmark_value> + <bookmark_value>regression curves in charts</bookmark_value> + <bookmark_value>trend lines in charts</bookmark_value> + <bookmark_value>mean value lines in charts</bookmark_value> </bookmark> <comment>only use trend line, not regression curve: i89823</comment> <bookmark xml-lang="en-US" branch="hid/.uno:InsertMenuTrendlines" id="bm_id2001709" localize="false"/> <bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/TP_TRENDLINE" id="bm_id2001710" localize="false"/> -<paragraph xml-lang="en-US" id="hd_id5409405" role="heading" level="1" l10n="CHG"><variable id="regression"><link href="text/schart/01/04050100.xhp">Trend Lines</link> -</variable></paragraph> - <paragraph xml-lang="en-US" id="par_id7272255" role="paragraph" l10n="CHG"><variable id="trendlinestext"><ahelp hid=".">Trend lines can be added to all 2D chart types except for Pie and Stock charts.</ahelp> -</variable></paragraph> - <embed href="text/schart/01/04030000.xhp#context"/> - <section id="howtoget"> - <embed href="text/schart/00/00000004.xhp#trendlines"/> - </section> -<comment>Linear</comment><bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/linear" id="bm_id6944181" localize="false"/> -<paragraph xml-lang="en-US" id="par_id5716727" role="paragraph" l10n="NEW"><ahelp hid="." visibility="hidden">A linear trend line is shown.</ahelp></paragraph> -<comment>Logarithmic</comment><bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/logarithmic" id="bm_id886257" localize="false"/> -<paragraph xml-lang="en-US" id="par_id5840021" role="paragraph" l10n="NEW"><ahelp hid="." visibility="hidden">A logarithmic trend line is shown.</ahelp></paragraph> -<comment>Exponential</comment><bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/exponential" id="bm_id8892483" localize="false"/> -<paragraph xml-lang="en-US" id="par_id9417096" role="paragraph" l10n="NEW"><ahelp hid="." visibility="hidden">An exponential trend line is shown.</ahelp></paragraph> -<comment>Power</comment><bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/power" id="bm_id7198400" localize="false"/> -<paragraph xml-lang="en-US" id="par_id8482924" role="paragraph" l10n="NEW"><ahelp hid="." visibility="hidden">A power trend line is shown.</ahelp></paragraph> -<comment>Show equation</comment><bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/showEquation" id="bm_id4724875" localize="false"/> -<paragraph xml-lang="en-US" id="par_id8962370" role="paragraph" l10n="NEW"><ahelp hid="." visibility="hidden">Shows the trend line equation next to the trend line.</ahelp></paragraph> -<comment>Show correlation coefficient (R2)</comment><bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/showCorrelationCoefficient" id="bm_id9068880" localize="false"/> -<paragraph xml-lang="en-US" id="par_id6889858" role="paragraph" l10n="CHG"><ahelp hid="." visibility="hidden">Shows the coefficient of determination next to the trend line.</ahelp></paragraph> - <paragraph xml-lang="en-US" id="par_id8398998" role="note" l10n="CHG">If you insert a trend line to a chart type that uses categories, like <emph>Line </emph>or <emph>Column, </emph>then the numbers 1, 2, 3, <emph>…</emph> are used as x-values to calculate the trend line.</paragraph> - <list type="ordered"> - <listitem> - <paragraph xml-lang="en-US" id="par_id5676747" role="paragraph" l10n="CHG">To insert trend lines for all data series, double-click the chart to enter edit mode. Choose <item type="menuitem">Insert - Trend Lines</item>, then select the type of trend line from None, Linear, Logarithmic, Exponential, or Power trend line.</paragraph> - </listitem> - <listitem> - <paragraph xml-lang="en-US" id="par_id4349192" role="paragraph" l10n="CHG">To insert a trend line for a single data series, select the data series in the chart, right-click to open the context menu, and choose <item type="menuitem">Insert - Trend Line</item>.</paragraph> - </listitem> - <listitem> - <paragraph xml-lang="en-US" id="par_id9337443" role="paragraph" l10n="NEW">To delete a single trend line or mean value line, click the line, then press the Del key.</paragraph> - </listitem> - <listitem> - <paragraph xml-lang="en-US" id="par_id4529251" role="paragraph" l10n="NEW">To delete all trend lines, choose <item type="menuitem">Insert - Trend Lines</item>, then select <emph>None</emph>.</paragraph> - </listitem> - </list> - <paragraph xml-lang="en-US" id="par_id296334" role="note" l10n="CHG">A trend line is shown in the legend automatically.</paragraph> + +<paragraph id="hd_id5409405" role="heading" level="1" xml-lang="en-US"> <variable id="regression"><link href="text/schart/01/04050100.xhp">Trend Lines</link></variable></paragraph> +<paragraph id="par_id7272255" role="paragraph" xml-lang="en-US"> <variable id="trendlinestext"> <ahelp hid=".">Trend lines can be added to all 2D chart types except for Pie and Stock charts.</ahelp> </variable> </paragraph> + +<section id="howtoget"> + <embed href="text/schart/00/00000004.xhp#trendlines"/> +</section> + +<comment>Linear</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/linear" id="bm_id6944181" localize="false"/> +<paragraph id="par_id5716727" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">A linear trend line is shown.</ahelp></paragraph> + +<comment>Logarithmic</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/logarithmic" id="bm_id886257" localize="false"/> +<paragraph id="par_id5840021" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">A logarithmic trend line is shown.</ahelp></paragraph> + +<comment>Exponential</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/exponential" id="bm_id8892483" localize="false"/> +<paragraph id="par_id9417096" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">An exponential trend line is shown.</ahelp></paragraph> + +<comment>Power</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/power" id="bm_id7198400" localize="false"/> +<paragraph id="par_id8482924" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">A power trend line is shown.</ahelp></paragraph> + +<comment>Polynomial</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/polynomial" id="bm_id180820161047491735" localize="false"/> +<paragraph id="par_id180820161052123210" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">A polynomial trend line is shown with a given degree.</ahelp></paragraph> + +<comment>Degree</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label3" id="bm_id180820161152296070" localize="false"/> +<paragraph id="par_id180820161102568315" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Degree of polynomial trend line.</ahelp></paragraph> + +<comment>Moving average</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/movingAverage" id="bm_id180820161104335824" localize="false"/> +<paragraph id="par_id180820161105546053" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">A moving average trend line is shown with a given period.</ahelp></paragraph> + +<comment>Period</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label4" id="bm_id180820161157368991" localize="false"/> +<paragraph id="par_id180820161107537745" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Number of points to calculate average of moving average trend line.</ahelp></paragraph> + +<comment>Trend line name</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label5" id="bm_id180820161429301956" localize="false"/> +<paragraph id="par_id180820161112599880" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Name of trend line in legend.</ahelp></paragraph> + +<comment>Extrapolate forward</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label7" id="bm_id180820161430141657" localize="false"/> +<paragraph id="par_id180820161117252261" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Trend line is extrapolated for higher x-values.</ahelp></paragraph> + +<comment>Extrapolate backward</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label8" id="bm_id180820161504266451" localize="false"/> +<paragraph id="par_id18082016111837138" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Trend line is extrapolated for lower x-values.</ahelp></paragraph> + +<comment>Force intercept</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/setIntercept" id="bm_id180820161122038174" localize="false"/> +<paragraph id="par_id180820161124272765" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">For linear, polynomial and exponential trend lines, intercept value is forced to a given value.</ahelp></paragraph> + +<comment>Intervept value</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/interceptValue" id="bm_id180820161125169514" localize="false"/> +<paragraph id="par_id180820161126064822" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Value of intercept if it is forced.</ahelp></paragraph> + +<comment>Show equation</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/showEquation" id="bm_id4724875" localize="false"/> +<paragraph id="par_id8962370" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Shows the trend line equation next to the trend line.</ahelp></paragraph> + +<comment>Show correlation coefficient (R2)</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/showCorrelationCoefficient" id="bm_id9068880" localize="false"/> +<paragraph id="par_id6889858" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Shows the coefficient of determination next to the trend line.</ahelp></paragraph> + +<comment>X name</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label6" id="bm_id180820161515523577" localize="false"/> +<paragraph id="par_id180820161133305870" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Name of X variable in trend line equation.</ahelp></paragraph> + +<comment>Y name</comment> +<bookmark xml-lang="en-US" branch="hid/modules/schart/ui/tp_Trendline/label9" id="bm_id180820161516105398" localize="false"/> +<paragraph id="par_id180820161134155865" role="paragraph" xml-lang="en-US"><ahelp hid="." visibility="hidden">Name of Y variable in trend line equation.</ahelp></paragraph> + +<paragraph id="par_id8398998" role="note" xml-lang="en-US">If you insert a trend line to a chart type that uses categories, like <emph>Line</emph> or <emph>Column</emph>, then the numbers 1, 2, 3, <emph>…</emph> are used as x-values to calculate the trend line. For such charts the XY chart type might be more suitable.</paragraph> + +<list type="unordered"> + <listitem> + <paragraph id="par_id4349192" role="paragraph" xml-lang="en-US">To insert a trend line for a data series, select the data series in the chart. Choose <item type="menuitem">Insert - Trend Lines</item>, or right-click to open the context menu, and choose <item type="menuitem">Insert - Trend Line</item>.</paragraph> + </listitem> + <listitem> <bookmark xml-lang="en-US" branch="hid/.uno:InsertMenuMeanValues" id="bm_id7854243" localize="false"/> -<paragraph xml-lang="en-US" id="par_id4072084" role="paragraph" l10n="NEW"><ahelp hid=".">Mean Value Lines are special trend lines that show the mean value. Use <item type="menuitem">Insert - Mean Value Lines</item> to insert mean value lines for data series.</ahelp></paragraph> + <paragraph id="par_id180820161539033867" role="paragraph" xml-lang="en-US">Mean Value Lines are special trend lines that show the mean value. Use <item type="menuitem">Insert - Mean Value Lines</item> to insert mean value lines for data series.</paragraph> <embed href="text/schart/01/04030000.xhp#context"/> - <paragraph xml-lang="en-US" id="par_id9569689" role="paragraph" l10n="NEW">The trend line has the same color as the corresponding data series. To change the line properties, select the trend line and choose <item type="menuitem">Format - Format Selection - Line</item>.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id9337443" role="paragraph" xml-lang="en-US">To delete a trend line or mean value line, click the line, then press the Del key.</paragraph> + </listitem> +</list> +<paragraph id="par_id296334" role="note" xml-lang="en-US">A trend line is shown in the legend automatically. Its name can be defined in options of the trend line.</paragraph> +<paragraph id="par_id9569689" role="paragraph" xml-lang="en-US">The trend line has the same color as the corresponding data series. To change the line properties, select the trend line and choose <item type="menuitem">Format - Format Selection - Line</item>.</paragraph> + +<bookmark xml-lang="en-US" branch="hid/.uno:InsertTrendlineEquationAndR2" id="bm_id2754601" localize="false"/> +<paragraph id="hd_id180820161534333508" role="heading" level="2" xml-lang="en-US">Trend Line Equation and Coefficient of Determination</paragraph> <bookmark xml-lang="en-US" branch="hid/.uno:InsertTrendlineEquation" id="bm_id2754600" localize="false"/> -<paragraph xml-lang="en-US" id="par_id846888" role="paragraph" l10n="NEW"><ahelp hid=".">To show the trend line equation, select the trend line in the chart, right-click to open the context menu, and choose <emph>Insert Trend Line Equation</emph>.</ahelp></paragraph> - <paragraph xml-lang="en-US" id="par_id8962065" role="paragraph" l10n="CHG">When the chart is in edit mode, %PRODUCTNAME gives you the equation of the trend line and the coefficient of determination R². Click on the trend line to see the information in the status bar.</paragraph> - <paragraph xml-lang="en-US" id="par_id1328470" role="note" l10n="CHG">For a category chart (for example a line chart), the trend line information is calculated using numbers 1, 2, 3, … as x-values. This is also true if your data series uses other numbers as names for the x-values. For such charts the XY chart type might be more suitable.</paragraph> - <paragraph xml-lang="en-US" id="par_id8092593" role="paragraph" l10n="CHG">To show the equation and the coefficient of determination, select the trend line and choose <item type="menuitem">Format - Format Selection - Equation</item>.</paragraph> -<paragraph xml-lang="en-US" id="par_id7971434" role="paragraph" l10n="CHG"><ahelp hid="." visibility="hidden">Enable Show equation to see the equation of the trend line.</ahelp></paragraph> -<paragraph xml-lang="en-US" id="par_id558793" role="paragraph" l10n="CHG"><ahelp hid="." visibility="hidden">Enable Show Coefficient of Determination to see the determination coefficient of the trend line.</ahelp></paragraph> - <paragraph xml-lang="en-US" id="par_id7735221" role="paragraph" l10n="NEW">You can also calculate the parameters using Calc functions as follows.</paragraph> - <paragraph xml-lang="en-US" id="hd_id5744193" role="heading" level="2" l10n="NEW">The linear regression equation</paragraph> - <paragraph xml-lang="en-US" id="par_id9251991" role="paragraph" l10n="NEW">The <emph>linear regression</emph> follows the equation <item type="literal">y=m*x+b</item>.</paragraph> - <paragraph xml-lang="en-US" id="par_id7951902" role="code" l10n="NEW">m = SLOPE(Data_Y;Data_X) </paragraph> - <paragraph xml-lang="en-US" id="par_id6637165" role="code" l10n="NEW">b = INTERCEPT(Data_Y ;Data_X) </paragraph> - <paragraph xml-lang="en-US" id="par_id7879268" role="paragraph" l10n="NEW">Calculate the coefficient of determination by</paragraph> - <paragraph xml-lang="en-US" id="par_id9244361" role="code" l10n="NEW">r² = RSQ(Data_Y;Data_X) </paragraph> - <paragraph xml-lang="en-US" id="par_id2083498" role="paragraph" l10n="NEW">Besides m, b and r² the array function <emph>LINEST</emph> provides additional statistics for a regression analysis.</paragraph> - <paragraph xml-lang="en-US" id="hd_id2538834" role="heading" level="2" l10n="NEW">The logarithm regression equation</paragraph> - <paragraph xml-lang="en-US" id="par_id394299" role="paragraph" l10n="NEW">The <emph>logarithm regression</emph> follows the equation <item type="literal">y=a*ln(x)+b</item>.</paragraph> - <paragraph xml-lang="en-US" id="par_id2134159" role="code" l10n="NEW">a = SLOPE(Data_Y;LN(Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="par_id5946531" role="code" l10n="NEW">b = INTERCEPT(Data_Y ;LN(Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="par_id5649281" role="code" l10n="NEW">r² = RSQ(Data_Y;LN(Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="hd_id7874080" role="heading" level="2" l10n="NEW">The exponential regression equation</paragraph> - <paragraph xml-lang="en-US" id="par_id4679097" role="paragraph" l10n="CHG"> For exponential trend lines a transformation to a linear model takes place. The optimal curve fitting is related to the linear model and the results are interpreted accordingly. </paragraph> - <paragraph xml-lang="en-US" id="par_id9112216" role="paragraph" l10n="NEW">The exponential regression follows the equation <item type="literal">y=b*exp(a*x)</item> or <item type="literal">y=b*m^x</item>, which is transformed to <item type="literal">ln(y)=ln(b)+a*x</item> or <item type="literal">ln(y)=ln(b)+ln(m)*x</item> respectively.</paragraph> - <paragraph xml-lang="en-US" id="par_id4416638" role="code" l10n="NEW">a = SLOPE(LN(Data_Y);Data_X) </paragraph> - <paragraph xml-lang="en-US" id="par_id1039155" role="paragraph" l10n="CHG">The variables for the second variation are calculated as follows:</paragraph> - <paragraph xml-lang="en-US" id="par_id7184057" role="code" l10n="NEW">m = EXP(SLOPE(LN(Data_Y);Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="par_id786767" role="code" l10n="NEW">b = EXP(INTERCEPT(LN(Data_Y);Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="par_id7127292" role="paragraph" l10n="NEW">Calculate the coefficient of determination by</paragraph> - <paragraph xml-lang="en-US" id="par_id5437177" role="code" l10n="NEW">r² = RSQ(LN(Data_Y);Data_X) </paragraph> - <paragraph xml-lang="en-US" id="par_id6946317" role="paragraph" l10n="NEW">Besides m, b and r² the array function LOGEST provides additional statistics for a regression analysis.</paragraph> - <paragraph xml-lang="en-US" id="hd_id6349375" role="heading" level="2" l10n="NEW">The power regression equation</paragraph> - <paragraph xml-lang="en-US" id="par_id1857661" role="paragraph" l10n="NEW"> For <emph>power regression</emph> curves a transformation to a linear model takes place. The power regression follows the equation <item type="literal">y=b*x^a</item> , which is transformed to <item type="literal">ln(y)=ln(b)+a*ln(x)</item>.</paragraph> - <paragraph xml-lang="en-US" id="par_id8517105" role="code" l10n="NEW">a = SLOPE(LN(Data_Y);LN(Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="par_id9827265" role="code" l10n="NEW">b = EXP(INTERCEPT(LN(Data_Y);LN(Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="par_id2357249" role="code" l10n="NEW">r² = RSQ(LN(Data_Y);LN(Data_X)) </paragraph> - <paragraph xml-lang="en-US" id="hd_id9204077" role="heading" level="2" l10n="NEW">Constraints<comment>UFI: is this still so?</comment></paragraph> - <paragraph xml-lang="en-US" id="par_id7393719" role="paragraph" l10n="CHG"> The calculation of the trend line considers only data pairs with the following values:</paragraph> - <list type="ordered"> - <listitem> - <paragraph xml-lang="en-US" id="par_id7212744" role="paragraph" l10n="NEW">logarithm regression: only positive x-values are considered,</paragraph> - </listitem> - <listitem> - <paragraph xml-lang="en-US" id="par_id1664479" role="paragraph" l10n="NEW">exponential regression: only positive y-values are considered,</paragraph> - </listitem> - <listitem> - <paragraph xml-lang="en-US" id="par_id8734702" role="paragraph" l10n="NEW">power regression: only positive x-values and positive y-values are considered.</paragraph> - </listitem> - </list> - <paragraph xml-lang="en-US" id="par_id181279" role="paragraph" l10n="NEW">You should transform your data accordingly; it is best to work on a copy of the original data and transform the copied data.</paragraph> - <paragraph xml-lang="en-US" id="hd_id7907040" role="heading" level="2" l10n="NEW">The polynomial regression equation</paragraph> - <paragraph xml-lang="en-US" id="par_id8918729" role="paragraph" l10n="NEW">A <emph>polynomial regression</emph> curve cannot be added automatically. You must calculate this curve manually. </paragraph> - <paragraph xml-lang="en-US" id="par_id33875" role="paragraph" l10n="NEW">Create a table with the columns x, x², x³, … , xⁿ, y up to the desired degree n. </paragraph> - <paragraph xml-lang="en-US" id="par_id8720053" role="paragraph" l10n="NEW">Use the formula <item type="literal">=LINEST(Data_Y,Data_X)</item> with the complete range x to xⁿ (without headings) as Data_X. </paragraph> - <paragraph xml-lang="en-US" id="par_id5068514" role="paragraph" l10n="NEW">The first row of the LINEST output contains the coefficients of the regression polynomial, with the coefficient of xⁿ at the leftmost position.</paragraph> - <paragraph xml-lang="en-US" id="par_id8202154" role="paragraph" l10n="NEW">The first element of the third row of the LINEST output is the value of r². See the <link href="text/scalc/01/04060107.xhp#Section8">LINEST</link> function for details on proper use and an explanation of the other output parameters.</paragraph> - <section id="relatedtopics"> - <paragraph xml-lang="en-US" id="par_id4562211" role="paragraph" l10n="CHG"><link href="text/schart/01/04050000.xhp">Y Error Bars tab page</link></paragraph> - </section> - </body> +<paragraph id="par_id8962065" role="paragraph" xml-lang="en-US">When the chart is in edit mode, %PRODUCTNAME gives you the equation of the trend line and the coefficient of determination R<sup>2</sup>, even if they are not shown: click on the trend line to see the information in the status bar.</paragraph> +<paragraph id="par_id846888" role="paragraph" xml-lang="en-US"><ahelp hid=".">To show the trend line equation, select the trend line in the chart, right-click to open the context menu, and choose <item type="menuitem">Insert Trend Line Equation</item>.</ahelp></paragraph> +<paragraph id="par_id8962066" role="paragraph" xml-lang="en-US">To change format of values (use less significant digits or scientific notation), select the equation in the chart, right-click to open the context menu, and choose <item type="menuitem">Format Trend Line Equation - Numbers</item>.</paragraph> +<paragraph id="par_id180820161627109994" role="paragraph" xml-lang="en-US">Default equation uses <item type="literal">x</item> for abscissa variable, and <item type="literal">f(x)</item> for ordinate variable. To change these names, select the trend line, choose <item type="menuitem">Format - Format Selection – Type</item> and enter names in <item type="literal">X Variable Name</item> and <item type="literal">Y Variable Name</item> edit boxes.</paragraph> + +<bookmark xml-lang="en-US" branch="hid/.uno:InsertR2Value" id="bm_id2754602" localize="false"/> +<paragraph id="par_id18082016163702791" role="paragraph" xml-lang="en-US">To show the coefficient of determination R<sup>2</sup>, select the equation in the chart, right-click to open the context menu, and choose <item type="menuitem">Insert R<sup>2</sup></item>.</paragraph> +<paragraph id="par_id180820161637028632" role="note" xml-lang="en-US">If intercept is forced, coefficient of determination R<sup>2</sup> is not calculated in the same way as with free intercept. R<sup>2</sup> values can not be compared with forced or free intercept.</paragraph> + +<paragraph id="hd_id180820161534333509" role="heading" level="2" xml-lang="en-US">Trend Lines Curve Types</paragraph> +<paragraph id="par_id18082016153820777" role="paragraph" xml-lang="en-US">Following regression types are available:</paragraph> + +<list type="unordered"> + <listitem> + <paragraph id="par_id180820161604098009" role="paragraph" xml-lang="en-US"><emph>Linear</emph> trend line: regression through equation <item type="literal">y=a∙x+b</item>. Intercept <item type="literal">b</item> can be forced.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id180820161612524298" role="paragraph" xml-lang="en-US"><emph>Polynomial</emph> trend line: regression through equation <item type="literal">y=Σ(a<sub>i</sub>∙x<sup>i</sup>)</item>. Intercept <item type="literal">a<sub>0</sub></item> can be forced. Degree of polynomial must be given (at least 2).</paragraph> + </listitem> + <listitem> + <paragraph id="par_id180820161612525364" role="paragraph" xml-lang="en-US"><emph>Logarithmic</emph> trend line: regression through equation <item type="literal">y=a∙ln(x)+b</item>.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id180820161612526680" role="paragraph" xml-lang="en-US"><emph>Exponential</emph> trend line: regression through equation <item type="literal">y=b∙exp(a∙x)</item>.This equation is equivalent to <item type="literal">y=b∙m<sup>x</sup></item> with <item type="literal">m=exp(a)</item>. Intercept <item type="literal">b</item> can be forced.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id180820161612527230" role="paragraph" xml-lang="en-US"><emph>Power</emph> trend line: regression through equation <item type="literal">y=b∙x<sup>a</sup></item>.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id180820161617342768" role="paragraph" xml-lang="en-US"><emph>Moving average</emph> trend line: simple moving average is calculated with the <emph>n</emph> previous y-values, <emph>n</emph> being the period. No equation is available for this trend line.</paragraph> + </listitem></list> + +<paragraph id="hd_id9204077" role="heading" level="2" xml-lang="en-US">Constraints</paragraph> +<paragraph id="par_id7393719" role="paragraph" xml-lang="en-US"> The calculation of the trend line considers only data pairs with the following values:</paragraph> + +<list type="unordered"> + <listitem> + <paragraph id="par_id7212744" role="paragraph" xml-lang="en-US">Logarithmic trend line: only positive x-values are considered.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id1664479" role="paragraph" xml-lang="en-US">Exponential trend line: only positive y-values are considered, except if all y-values are negative: regression will then follow equation <item type="literal">y=-b∙exp(a∙x)</item>.</paragraph> + </listitem> + <listitem> + <paragraph id="par_id8734702" role="paragraph" xml-lang="en-US">Power trend line: only positive x-values are considered; only positive y-values are considered, except if all y-values are negative: regression will then follow equation<item type="literal"> y=-b∙x<sup>a</sup></item>.</paragraph> + </listitem> +</list> +<paragraph id="par_id181279" role="paragraph" xml-lang="en-US">You should transform your data accordingly; it is best to work on a copy of the original data and transform the copied data.</paragraph> + +<paragraph id="hd_id180820161528021520" role="heading" level="2" xml-lang="en-US">Calculate Parameters in Calc</paragraph> +<paragraph id="par_id7735221" role="paragraph" xml-lang="en-US">You can also calculate the parameters using Calc functions as follows.</paragraph> + +<paragraph id="hd_id5744193" role="heading" level="3" xml-lang="en-US">The linear regression equation</paragraph> +<paragraph id="par_id9251991" role="paragraph" xml-lang="en-US">The <emph>linear regression</emph> follows the equation <item type="literal">y=m*x+b</item>.</paragraph> +<paragraph id="par_id7951902" role="code" xml-lang="en-US">m = SLOPE(Data_Y;Data_X) </paragraph> +<paragraph id="par_id6637165" role="code" xml-lang="en-US">b = INTERCEPT(Data_Y ;Data_X) </paragraph> +<paragraph id="par_id7879268" role="paragraph" xml-lang="en-US">Calculate the coefficient of determination by</paragraph> +<paragraph id="par_id9244361" role="code" xml-lang="en-US">r<sup>2</sup> = RSQ(Data_Y;Data_X) </paragraph> +<paragraph id="par_id2083498" role="paragraph" xml-lang="en-US">Besides m, b and r<sup>2</sup> the array function <emph>LINEST</emph> provides additional statistics for a regression analysis.</paragraph> + +<paragraph id="hd_id2538834" role="heading" level="3" xml-lang="en-US">The logarithmic regression equation</paragraph> +<paragraph id="par_id394299" role="paragraph" xml-lang="en-US">The <emph>logarithmic regression</emph> follows the equation <item type="literal">y=a*ln(x)+b</item>.</paragraph> +<paragraph id="par_id2134159" role="code" xml-lang="en-US">a = SLOPE(Data_Y;LN(Data_X)) </paragraph> +<paragraph id="par_id5946531" role="code" xml-lang="en-US">b = INTERCEPT(Data_Y ;LN(Data_X)) </paragraph> +<paragraph id="par_id5649281" role="code" xml-lang="en-US">r<sup>2</sup> = RSQ(Data_Y;LN(Data_X)) </paragraph> + +<paragraph id="hd_id7874080" role="heading" level="3" xml-lang="en-US">The exponential regression equation</paragraph> +<paragraph id="par_id4679097" role="paragraph" xml-lang="en-US"> For exponential trend lines a transformation to a linear model takes place. The optimal curve fitting is related to the linear model and the results are interpreted accordingly.</paragraph> +<paragraph id="par_id9112216" role="paragraph" xml-lang="en-US">The exponential regression follows the equation <item type="literal">y=b*exp(a*x)</item> or <item type="literal">y=b*m^x</item>, which is transformed to <item type="literal">ln(y)=ln(b)+a*x</item> or <item type="literal">ln(y)=ln(b)+ln(m)*x</item> respectively.</paragraph> +<paragraph id="par_id4416638" role="code" xml-lang="en-US">a = SLOPE(LN(Data_Y);Data_X) </paragraph> +<paragraph id="par_id1039155" role="paragraph" xml-lang="en-US">The variables for the second variation are calculated as follows:</paragraph> +<paragraph id="par_id7184057" role="code" xml-lang="en-US">m = EXP(SLOPE(LN(Data_Y);Data_X)) </paragraph> +<paragraph id="par_id786767" role="code" xml-lang="en-US">b = EXP(INTERCEPT(LN(Data_Y);Data_X)) </paragraph> +<paragraph id="par_id7127292" role="paragraph" xml-lang="en-US">Calculate the coefficient of determination by</paragraph> +<paragraph id="par_id5437177" role="code" xml-lang="en-US">r<sup>2</sup> = RSQ(LN(Data_Y);Data_X) </paragraph> +<paragraph id="par_id6946317" role="paragraph" xml-lang="en-US">Besides m, b and r<sup>2</sup> the array function LOGEST provides additional statistics for a regression analysis.</paragraph> + +<paragraph id="hd_id6349375" role="heading" level="3" xml-lang="en-US">The power regression equation</paragraph> +<paragraph id="par_id1857661" role="paragraph" xml-lang="en-US"> For <emph>power regression</emph> curves a transformation to a linear model takes place. The power regression follows the equation <item type="literal">y=b*x^a</item> , which is transformed to <item type="literal">ln(y)=ln(b)+a*ln(x)</item>.</paragraph> +<paragraph id="par_id8517105" role="code" xml-lang="en-US">a = SLOPE(LN(Data_Y);LN(Data_X)) </paragraph> +<paragraph id="par_id9827265" role="code" xml-lang="en-US">b = EXP(INTERCEPT(LN(Data_Y);LN(Data_X)) </paragraph> +<paragraph id="par_id2357249" role="code" xml-lang="en-US">r<sup>2</sup> = RSQ(LN(Data_Y);LN(Data_X)) </paragraph> + +<paragraph id="hd_id7907040" role="heading" level="3" xml-lang="en-US">The polynomial regression equation</paragraph> +<paragraph id="par_id8918729" role="paragraph" xml-lang="en-US">For <emph>polynomial regression</emph> curves a transformation to a linear model takes place.</paragraph> +<paragraph id="par_id33875" role="paragraph" xml-lang="en-US">Create a table with the columns x, x<sup>2</sup>, x<sup>3</sup>, … , x<sup>n</sup>, y up to the desired degree n. </paragraph> +<paragraph id="par_id8720053" role="paragraph" xml-lang="en-US">Use the formula <item type="literal">=LINEST(Data_Y,Data_X)</item> with the complete range x to x<sup>n</sup> (without headings) as Data_X. </paragraph> +<paragraph id="par_id5068514" role="paragraph" xml-lang="en-US">The first row of the LINEST output contains the coefficients of the regression polynomial, with the coefficient of xⁿ at the leftmost position.</paragraph> +<paragraph id="par_id8202154" role="paragraph" xml-lang="en-US">The first element of the third row of the LINEST output is the value of r<sup>2</sup>. See the <link href="text/scalc/01/04060107.xhp#Section8">LINEST</link> function for details on proper use and an explanation of the other output parameters.</paragraph> + +<section id="relatedtopics"> + <paragraph id="par_id4562211" role="paragraph" xml-lang="en-US"><link href="text/schart/01/04050000.xhp">X/Y Error Bars</link></paragraph> + <paragraph id="par_id4562212" role="paragraph" xml-lang="en-US"><link href="text/scalc/01/04060107.xhp#Section8">LINEST</link> function</paragraph> + <paragraph id="par_id4562216" role="paragraph" xml-lang="en-US"><link href="text/scalc/01/04060107.xhp#Section7">LOGEST</link> function</paragraph> + <paragraph id="par_id4562213" role="paragraph" xml-lang="en-US"><link href="text/scalc/01/04060185.xhp#slope">SLOPE</link> function</paragraph> + <paragraph id="par_id4562214" role="paragraph" xml-lang="en-US"><link href="text/scalc/01/04060181.xhp#intercept">INTERCEPT</link> function</paragraph> + <paragraph id="par_id4562215" role="paragraph" xml-lang="en-US"><link href="text/scalc/01/04060181.xhp#rsq">RSQ</link> function</paragraph> +</section> +</body> + </helpdocument> |