Friday, October 9, 2015

Different but close

In a GAMS model we calculated some numbers. I expected them to be the same. I saw:

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OK, small difference. Let’s increase the number of decimals:

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No cigar. All right. The difference is beyond the 8th decimal place. Lets have a look in the GDX viewer, which can show things in MAX precision:

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Still no luck in viewing the difference between v(c) and v(a),v(b). GDXDUMP?

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Export to Excel?

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Using PUT?

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The PUT statement is limited to 15 decimal places.

We can show some indirect evidence that v(c) actually a little bit larger than v(a) or v(b):

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The last bit is different.

Using a C# program writing with d.ToString(“G17’') we finally see the real cause:

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Still have not found a easy way (without doing some programming) of showing the numbers v(i) in full precision. Looks like an obvious thing to ask for.