Android app Returning NaN

Question

Why does calcGPA keep saying it equals NaN? I make sure it is not undefined.

double gradesMultiplied = ((quantityA * 4.00) + (quantityAMin * 3.70) + (quantityBPlu * 3.30) + (quantityB * 3.00) + (quantityBMin * 2.70) + (quantityCPlu * 2.30) + (quantityC * 2.00) + (quantityCMin * 1.70) + (quantityDPlu * 1.30) + quantityD + (quantityDMin * 0.70));
double gradesAdded = (quantityA + quantityAMin + quantityBPlu + quantityB + quantityBMin + quantityCPlu + quantityC + quantityCMin + quantityDPlu + quantityD + quantityDMin + quantityF);
double calcGPA = gradesMultiplied / gradesAdded;

I suspect that both `gradesMultiplied` and `gradesAdded` are zero. — Andy Turner, Apr 20 '16 at 21:18
Or one of the many quantities you are adding is `NaN` already. — Andy Turner, Apr 20 '16 at 21:20
This would be much easier if you used an array instead of these `quantityXXX` variables. — Andy Turner, Apr 20 '16 at 21:23
try printing out the values of gradesMultiplied and gradesAdded before you try the division (use System.out.println(gradesMultiplied) or use a debugger and see what the values are — Brian Pipa, Apr 20 '16 at 21:27

score 0 · Accepted Answer · edited May 23 '17 at 12:23

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NaN is Not a Number, try explicitly converting all values to numbers in the beginning.

Also looking at this is it possible you are dividing zero by zero?

"NaN" stands for "not a number". "Nan" is produced if a floating point operation has some input parameters that cause the operation to produce some undefined result. For example, 0.0 divided by 0.0 is arithmetically undefined. Taking the square root of a negative number is also undefined.

edited May 23 '17 at 12:23

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answered Apr 20 '16 at 21:16

workabyte

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that was what i was pointing out just didnt type it right, I updated though. Thanks & cheers – workabyte Apr 20 '16 at 21:19
I know i am not dividing by zero because i make sure gradesAdded is not a zero – tchristofferson Apr 20 '16 at 21:20
@tchristofferson then odds are there is a NaN value in that chain – workabyte Apr 20 '16 at 21:21

score 0 · Answer 2 · answered Apr 21 '16 at 22:01

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I fixed it everybody. I had to put the first 2 lines in my methods that add the quantity when pushing button.

answered Apr 21 '16 at 22:01

tchristofferson

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Android app Returning NaN

2 Answers2