I have a dataset I'm visualizing with DX (obviously!!)
I want to convert the values to logs before displaying them. I have got a ... mark(data) -> compute(log10(a)) -> .... in my net, but get the error: ERROR: Compute: Bad parameter: taking logarithm of non-positive number in data element 12 If I fork the data going into the compute module to a Describe module as well, I get: Object Details: There are 513279 data items, each is of type float (4-byte or real*4). The positions are enclosed within the box defined by the corner points: [ 170.243 -53.4077 -640 ] and [ 170.499 -53.4032 -0 ] Data range is: minimum = 0, maximum = 0.00151444, average = 3.54352e-06 The data range suggests there are NO negative values & a grep through the input datafile also finds none. If I change the Compute to be log10(a+0.000000001) instead of log10(a) it works. To me this suggests that some 0 values are being interpreted as very small negatives by compute. Given I get -zero Z values in the positions (as shown in the describe output above), this suggests DX is quite happy with the value of negative zero for a scalar. Is my assumption reasonable, & is there a more elegant fix for this??? Thanks, Brent Wood
