Creating the new columns and formulas for the Weibull Regression with voltage
and temperature stresses tutorial
By Barry Eggleston
First create a column containing the natural log of voltage:
Click on "Cols" on the menu bar:
Then click on "New Column…"
A dialog box will appear. Rename the column as LogVoltage.
Click on the selection button to the right of the word "Data Source" in
order to change the data source to a formula. Note: when one first
opens this window the data source is "No Formula". Select Formula,
then click on OK.
Once you click on OK , a calculator window will appear. The calculator
window allows one to assign formulas to columns.
Click on Transcendental, then click on Natural Log. Finally click
on Voltage. The calculator window should now appear like the following:
Click on Evaluate, and then the X button in the upper right corner of the
calculator window.
You should now have a LogVoltage column in the data table.
Now create a TempTrans column, repeating the same necessary steps described
above:
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Click on Cols | New Columns..
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Rename the column TempTrans
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Change the data source to formula
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Click on OK.
To create the calculator function
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Click on the division symbol
-
Enter 11605
-
Click on the denominator box, and then click on either of the parenthesis
buttons
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Click on Temperature
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Click on the addition symbol
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Enter 273.
The calculator window should look like the following:
Click on Evaluate, and then click on the X button in the upper right
hand corner of the calculator window.
Click here and go back to the tutorial, "Weibull
Regression with voltage and temperature stresses."