Why does legacy code scale variables by 2^16?

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KAE 2017-11-20

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https://ww2.mathworks.cn/matlabcentral/answers/368216-why-does-legacy-code-scale-variables-by-2-16

编辑： KAE 2017-11-22

I am trying to understand some legacy Matlab code, and was puzzled to note that many variables are multiplied or divided by 2^16. After some digging I found this is the largest number that a 16-bit (unsigned) integer can hold, see here. I believe the code originated in C or C#. I have two questions: (1) Could the code author be using this factor to force the variable to be a float? (2) If so, can I delete all the 2^16 factors without affecting the values in Matlab?

Here is an example,

SOME_THRESHOLD = floor(0.010 * 65536); % Author's comment indicates this is supposed to represent 10%

SOME_THRESHOLD gets passed in to a function which where all the other variables have been multiplied by either 65536 or 2^16 prior to arithmetic operations; floor and abs are also used.

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Image Analyst 2017-11-21

I don't see the example in your original/edited question. But ... good luck though.

Christoph F. 2017-11-22

I think the original author tried to make the MatLAB script use exactly the same numbers as the C code would.

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KAE 2017-11-22

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https://ww2.mathworks.cn/matlabcentral/answers/368216-why-does-legacy-code-scale-variables-by-2-16#answer_292603

编辑：KAE 2017-11-22

Just to close this question out, based on all the comments and info at the links, it appears that the 2^16 factors are for binary scaling in the original C code. There could be numerical differences if the 2^16 factors were removed but they are small for my application. Thanks for all your help!