NaN error in calculation

[Jacob1]

Hi everyone,

I can´t seem to figure out why the following calculation returns the error "NaN".

((-(-(10/20-1)^0.88))+1)/((1-2)*(-(-(10/20-1)^0.88))+1)

The exact same calculation in typed into Microsoft excel works just fine.

Any hints would be much appreciated.

[startz]

@Jacob1

((-(-(10/20-1)^0.88))+1)/((1-2)*(-(-(10/20-1)^0.88))+1)

@Jacob1

Hi everyone,

I can´t seem to figure out why the following calculation returns the error "NaN".

((-(-(10/20-1)^0.88))+1)/((1-2)*(-(-(10/20-1)^0.88))+1)

The exact same calculation in typed into Microsoft excel works just fine.

Any hints would be much appreciated.

Order of operations must be different. R seems to be doing the exponentiation before the negation while Excel does it the other way around. (You can add parentheses to control this if you like.)

[arthur.t]

Looks like it all stem from this

-(10/20-1)^0.88

or more simply

-(-0.5)^0.88

R raises -0.5 to the power 0.88 which is an imaginary number.

For some reason, Excel applies the negative to the quantity before the exponent, so is evaluating 0.5^0.88.

I'd take a look at that part of the equation and re-write so it is more explicit what that first "-" is supposed to do.

[Jacob1]

I see, thanks a lot. Adding parenthesis did the job.

Sorry for wasting your time with this one!!