Mathe equation error

[adam_lhadi]

HI

when using this piece of code

"1".Expenential_resault := ("1".Expenential_cof )**(("1".linear_Rows) -1); i get an error (Pic 1) how to fix it

the purpose is to get a resault of (+1 -1 +1 -1 +1........)

when i change the value manually it works great

"1".Expenential_resault := ("1".Expenential_cof )**(1 or 2 or 3... so on)

also this code gives me an error

"1".Expenential_resault := (-1)**(("1".linear_Rows) -1) using -1 gives an error but declaring a constant in data block with -1 value solve the problem ,so what's the diffrence

kind regards

[drbitboy]

if you change the "(3)" to "(3.0)" in the code that works it will probably fail.

try casting .linear_Rows as an integer. It might work.


The other option would be to simply toggle the sign of the result based on the result of of (.linear_Rows MOD 2). e.g. something like this:

"1".Expenential_resault := 1.0 - (2.0 * (("1".linear_Rows - 1) MOD 2.0));

[drbitboy]

Another option, that might work would be

"1".Expenential_resault := ("1".Expenential_cof) ** REAL_TO_INT("1".linear_Rows - 1));

Although I don't know offhand what the equivalent is in SCL for that REAL_TO_INT function.

[MaxK]

qNaN. Possibly due to data type mismatch. Finding the problem is not easy.

Easier to use the #2 solution.

or

"1".Expenential_resault := "1".Expenential_resault * -1

[L D[AR2,P#0.0]]

If you attempt to use a hard coded negative number in a power operation you will get a compiler error 'negative base specified for power operation'


If you attempt to use a variable that is negative in a power operation you will get a run time error which you test for by checking the ENO variable in SCL.