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IsoSource Help

# Calculating the Data

Select [Calc] from the menu bar

Enter the filename, or Select an existing filename to save to and then click on the [Save] button

The program now starts to process your data file.

If this message appears then there were no solutions found You may need to adjust the Tolerance, or Increment Values. A few screens down we did this and reran the dataset.

After the program is done performing calculations the time message will appear. This is useful in estimating the amount of time it will take to process a dataset for future runs.

To try and get some results we increased the Tolerance value from .01 to .05 and reran the data

We used the same output filename and then clicked on the [Save] button

The program processed the data again.

This time there was no "0 solutions found message", so the program found some solutions.

To eliminate roundoff error, IsoSource uses integer comparisons in determining the feasibility of each source combination.
To represent the appropriate variables as integers, IsoSource determines the maximum number of decimal places needed
and uses a multiplier to transform decimal numbers into integers (e.g., 1.234 x 1000 = 1234).
The number of decimal places is determined by the maximum of the following:
1. number of decimal places in the Increment value plus the maximum number of decimal places in the source isotopic signatures
2. number of decimal places in the mixture signatures
3. number of decimal places in the Tolerance
These are all user-specified values in the input data set. The maximum number of decimal places that IsoSource can accomodate is 6.
If there are more than 6 decimal places, a window pops up with the message "Can't run the calculation. The number of decimal places exceeds
the maximum of 6. See the CALC section of the documentation for further details." If this happens, then change the number of decimal places in
the appropriate user-specified data values, depending on which of the 3 situations above applies.