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When a fit process is chosen from the data input menu, e.g. polynomial or linear least squares, then a new window will open showing the results of the fit. The linear least squares and parabola result windows are shown below as examples.
Whichever fit is chosen, the corresponding window will open showing the calculated parameters for the fitted equation.
All these windows have one thing in common - the buttons at the foot of the window labelled Graph and Save.
Clicking on Graph will open a graph window showing the data points and the line calculated from the fitted equation on suitably scaled axes. The style of the graph will follow the settings in Choices, but can be modified easily if necessary. See the Graph and Graph layout options pages for more information.
Clicking on Save will produce a Save as dialogue, from which a text file can be saved (or loaded into a suitable application). This text file contains the information produced by the fitting process. In addition, depending on the actual fit carried out, it may also list the point data as entered and as calculated from the fit equation, etc.
An example from a linear fit is shown below (some data points have been omitted from the full data set).
Results of best line fit
========================
Slope = 3.54402
Intercept on y axis = -48.4203
Correlation coefficient = 0.99944
Standard error of slope = 0.0395555
Standard error of intercept = 1.39883
Sum of errors squared = 18.0605
Error in Y value for each point
===============================
X obs Y obs Y calc Error
---- ----- ------ -----
16 9 8.28402 0.715977
19 18 18.9161 -0.916076
29 53 54.3563 -1.35625
33 69 68.5323 0.467678
36 80 79.1644 0.835625
41 97 96.8845 0.115537
45 113 111.061 1.93947
48 123 121.693 1.30741
52 133 135.869 -2.86866
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The graph window
GraphDraw is © Chris Johnson, 2014
Email:chris@chris-johnson.org.uk
This document last modified on 15th August 2015