| Slide Number 1
|Welcome to the tutorial on Data fitting in Grace.|
| Slide Number 2
| In this tutorial, we will
| Slide Number 3
System and Software Requirement
| To record this tutorial, I am using
| Slide Number 4
| To follow this tutorial,
| Slide Number 5
| * Data fitting is a process to find a mathematical relation between two variables.
|Go to Desktop.||Go to Desktop.|
|Hover mouse over file, line-fit.txt.|| Notice the file, line-fit.txt.
This file is provided to you in the Code Files link.
I have downloaded, extracted and saved the file to the Desktop directory.
|Show screenshot of Grace read-sets dialogue box.||Next, open the Grace program and load this file to plot an XY graph.|
|Show screenshot of XY data set, and autoscale data.||Choose XY data set, and autoscale data.|
|Hover mouse over the data.||Next I will format the plot.|
|Show screenshot for : change the symbol, size, pattern. choose filled circle adjust size to 35.||I have changed the symbols, line style, tick marks and axis labels.|
|Move the cursor along the data points.|| The data points do not lie on a straight line.
The data points look scattered around a straight line.
|Cursor on the graph.|| We will fit this data to a straight line.
For a straight line, this is process is called linear regression.
| Slide Number 6
Equation in two variables
| A straight line is described by an equation in two variables,
The equation has the form, y equals mx+c.
Here, m is the slope of the line and c is the intercept.
|Go to Data,Transformations.|| Go to Data and select Transformations.
Notice the available options.
|Choose Regression.|| Choose Regression from the list.
A Regression dialogue box opens.
| Hover mouse over S(0).
Choose dataset (S0).
| Choose the data set of interest from Apply to set.
Currently only a single set is loaded and it is shown as S0.
The next number is the number of points that are present in the dataset.
|Choose linear for Type of fit.|| If many datasets are loaded more sets will be seen, in the Apply to set box.
Choose linear for Type of fit.
|for Load, choose Fitted values.||In the Load drop-down, choose Fitted values.|
|For restrictions choose None.|| For restrictions choose None.
If only part of the data set needs to be fitted, enter the required range.
| Hover mouse over start load at and stop load at values.
Click on Accept.
| We can also specify the start load at and stop load at values in the form.
I will leave it as is and will not make changes here.
Click on Accept to run the data fitting.
|Show the Grace console window, and output values.|| The data fitting algorithm runs.
A Grace console window appears with mathematical details.
|Scroll in the Console window to show the values.|| We can see the equation used for the fitting.
The output values of residual, slope, intercept and other parameters are seen.
|Show on screen S(1) dataset showing in panel.|| The fitted line appears on the screen.
The fitted values are loaded in a different set, S1.
|Click on File, Save.||Click on File, Save to save the parameters.|
|Show the opened Grace: Save logs.||The Grace: Save logs window opens.|
|Type line-regression.txt in Save to file.||In Save to file text box, type the filename as line-regression.txt.|
|Click on Apply and click to close.||Click on Apply and then click on Close to close the dialogue box.|
|Close Grace:Console by File, Close or Esc||Close the Grace Console by File, Close or press theEsc key.|
|Click on Close in Regression window.||Click on Close in the Regression window.|
|Double click on the line in the graph.|| Double click on the line in the graph.
Grace Set appearance window opens.
|In select set form, select (S1) data set.|| In the select set form, select S1 data set.
This is the fitted data.
|Right-click, select Edit, In spreadsheet option.|| Right click to open the context menu.
Select Edit, and in In spreadsheet option.
The Grace: Spreadsheet dataset editor appears.
|Hover mouse over x and y columns.|| Notice the x and corresponding fitted y values of the fitted data.
These values are different from the input data.
|Hover mouse over the fitted line.||This line fits the input data best, with a linear equation.|
|Close the Spreadsheet dataset Editor.||Close the Spreadsheet dataset Editor.|
|Hover mouse over the two datasets.|| The original data set and the fitted values are the 2 datasets in the graph.
Datasets are labeled as [S0] for first set and [S1] for the second set.
|Cursor on the graph.|| We can add more datasets to this graph panel.
For this load the data using the Data, import, ASCII option from the menu.
|Cursor on the plot window.||Next, we will add legends to the plot.|
|Double click on the line to open Set Appearance window.||Open the Set Appearance window and choose the dataset S0.|
| Type Data in String field.
Click on Apply.
| Under Legend, in the String field, type Data as the legend label.
Click on Apply.
|Choose S1 dataset.||Next choose S1 dataset from the Select set data form.|
|Type Fitted data for the legend string and click on Apply.||Here, I will type Fitted data for the legend and click on Apply.|
|Click on Close to close Set Appearance window.||Close the Set Appearance window.|
|Cursor the the legend.||For some users, the legend position may be outside the graph border.|
|Cursor in the legend box and press Ctrl+L .|| To reposition the legends, place the cursor in the legend box.
Then press Control and L keys together.
|Show the cursor change on the screen.||The cursor changes to a pointer.|
|Left click and drag the legend box to the desired position.||Left click and drag the legend box to the desired position.|
|Press Enter and then press Esc key.|| Then, press Enter.
Press the Escape key to exit the movement mode.
|Open Graph appearance, Legend tab.|| Next, open the Graph appearance window.
In the window, click on the Legends tab, to format the legend fonts.
|Move size slider to 70.|| Under the text properties, move the character size slider to 70.
The legends look very large compared to the graph.
|Click on the font drop-down.||I will retain the font type as Times-Roman.|
|Click on Apply.||Click on Apply to apply the changes.|
|Click on the legend boxtab.||Click on the legend box tab.|
|Hover mouse next to Legend location.|| We can also specify the position of the legend in the location section.
I will leave it as is.
|In pattern drop-down, choose None.||In the Frame line section, for Pattern, I will choose None.|
|Click on Apply.|| Click on Apply.
This will remove the legend frame box.
|Click on Close.||Then Close the dialogue box.|
|Show screenshot of save as dialogue box with name filled in as regression.agr.|| Now save the project in the Desktop directory.
I will use the file name regression dot agr.
|Press Ctrl+Q||Press Control Q or Click on File, Exit to exit Grace.|
| Slide Number 7
| In this tutorial we,
| Slide Number 8
| For assignment activity, please do the following.
(parabola1.txt & parabola2.txt)
| Slide Number 9
|Show the glimpse of assignment.||Your completed assignment may look similar to this.|
| Slide Number 10
Spoken Tutorial Project
| This video summarizes the Spoken Tutorial Project.
Please download and watch it.
| Slide Number 11
Spoken Tutorial workshops
| The Spoken Tutorial Project team:
For more details, please write to us.
| Slide Number 12
Forum for specific questions:
|Please post your timed queries in this forum.|
| Slide Number 13
| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link.
| This is Rani from IIT Bombay.
Thank you for joining.