Hello, I was using BCON to prepare a simulation but ran into a problem as it (ICON does the smae) has rounded XORIG from -903,125 to 903,000. My guess is that the issue is originated by the lines: & /10X, 'XORIG = ', 1PE14.0 (at opn_ic_file.F) 94280 FORMAT( 10X, 'XORIG1 = ', 1PE12.0,…

The lines causing the rounding are at setgriddefs.f90: IF ( ( gdtyp_gd == lamgrd3 ) .AND. ( wrf_lc_ref_lat > -900.0 ) ) THEN ! Force XORIG and YORIG to be even increments of 0.5*delta-X. xtemp = xorig_ctm / 500.0 ytemp = yorig_ctm / 500.0 xtemp = FLOAT(NINT(xtemp)) …

No, to my knowledge, neither ICON nor BCON apply any rounding to projection parameters in their internal calculations. Instead, they check for consistency of these parameters across input files and the GRIDDESC file. In case inconsistencies are found, diagnostic messages are written to the log file …

I do not get any error. However, and when I dump the files generated by either ICON or BCON, the attribute XORIG is set to -903,000 (when it should be -903,125). YORIG is set up correctly to -637,500. It’s an odd error (never happened before). I just checked (should probably have done this earlier)…

Does commenting out those lines give you the desired result?

Hi @cgnolte, Sorry as I had to be somewhere else and only had time to quote the lines. Yes, the lines can be commented out to prevent the rounding. P.S. I changed the title of the thread to reflect the root of the issue more accurately.

@afernandez – Thank you for raising this issue. We have stumbled on the same problem in-house, and the lines of code that you identified will either be removed or modified to address this issue. In your case, I believe you can safely proceed by either commenting out or removing those lines, as they…

Hey sir，I’ll ask you a question.The value of PGAM and XCENT I run mcip output is 111.455001831055，but the output values of icon and bcon continue to run are111.455，there is a similar situation for YCENT.I want to ask how to solve it [image] [image]

Approaches on how to do this consistency checking described here may help to resolve your issue. [image] Icon nesting error CMAQ-PREP This doesn’t quite work. Assuming the program does a perfect job of rounding (something not guaranteed by the Fortran Standard), no such l…

@TJDOFLEARN – Which version of MCIP are you using? –Tanya

How to change the MCIP rounding?

CMAQ

lizadams February 25, 2025, 4:05pm 10

Approaches on how to do this consistency checking described here may help to resolve your issue.

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How to change the MCIP rounding?

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