topic Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up. in Data Management Questions

Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Wed, 03 Oct 2018 05:11:27 GMT

I am attempting to convert the azimuth field in a shapefile from degrees to radians using the Field Calculator, but after providing the equation, all the attributes in the new field show up as zero. Equation is [azimuth]*(pi/180). I also tried the calculation using the approximate decimal value of pi/180 and got the same result.

Attached are screenshots of the dialogue window and the problem with the zeros in the attribute table.

Is there a way to fix this without having to use Python or R, and if so how?

Any help would be greatly appreciated!

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Wed, 03 Oct 2018 09:08:46 GMT

try the python parser You get access to the math functions

!azim! is the name of an azimuth field in a table

math.radians(!azim!)

!azim!*math.pi/180

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 02:09:20 GMT

I tried that code using the Python parser and got an error that said: "There was a failure during processing. Please check the Geoprocessing window for details." I received Error 000539: Invalid field azim.

I tried again using my field's name, azimuth, in place of azim, and got the same dialogue but with Error 000539: SyntaxError: invalid syntax, (<expression>, line 2). Should there be another pair of parentheses somewhere, perhaps around pi/180?

The only two results I have gotten in all my attempts so far to convert azimuth to radians are either all zeros or this kind of error.

Thanks for your help! Any other suggestions are greatly appreciated.

Best,

Rachel DiPietro

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 02:50:45 GMT

why don't you screen the table and your field calculator expression.

it would be easier than working with textual descriptions

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 03:12:09 GMT

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 03:27:32 GMT

you use one or the other in the calculation expression... not both

math.radians(45) == 45*math.pi/180.

True

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 03:45:10 GMT

Okay, my mistake. Here's the new result.

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 04:37:36 GMT

is the field a 'Double' type or is it 'Long' or 'Short'

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 14:16:21 GMT

It is a 'Short' type.

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 16:43:57 GMT

It should be Double if you want to see decimal points in your numbers... short and long are integers

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 19:16:39 GMT

It worked!

Thank you so much for all your help!

Best,

Rachel DiPietro

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 19:21:18 GMT

Rachel... glad it worked out

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 19:35:38 GMT

Now there is a new error...

The syntax worked for the first two data sets out of seven after switching to 'Double' fields, but now I am getting this:

I have tried each of the syntax examples provided, exactly as they are with my field name. I changed none of the syntax from the first two datasets that did work vs the two I am working on now that don't work, and yet I received a general syntax error.

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 19:48:10 GMT

If the inputs aren't numeric (ie numbers) then Double won't work. And the error is less important to me than showing the table and the inputs to the field calculator

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 19:49:14 GMT

Whoops. Looks like I had forgotten the switch to Python parser. My apologies for the inconvenience!

Thank you again!

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

RachelDiPietro — Thu, 04 Oct 2018 19:51:59 GMT

It was the parser. I had Python code on a VB Script. Working fine now.

Thank you again!

Re: Converting azimuth from degrees to radians using Field Calculator; only zeros show up.

DanPatterson_Retired — Thu, 04 Oct 2018 19:57:23 GMT

progress on multiple fronts... that is good