call routine in IDL programming lanuage

Question

I am new and learning IDL on a steep curve. I have 2 PROS first one follows

Pro READ_Netcdf1,infile,temperature,time,print_prompts=print_prompts 

COMPILE_OPt IDL2

infile='D:/Rwork/dataset/monthly_mean/version_2C/air.2m.mon.mean.nc'


IF (N_Elements(infile) EQ 0 ) Then STOP,'You are being silly, you must specify infile on call'



print,infile
iid = NCDF_OPEN(infile)
NCDF_VARGET, iid, 'time',  time              ; Read time
NCDF_VARGET, iid, 'air',   temperature       ; Read surface average temperature
NCDF_VARGET, iid, 'lat',   latitude          ; Read Latitude
NCDF_VARGET, iid, 'lon',   longitude         ; Read Longitude
NCDF_CLOSE, iid                              ; Close Input File

Centigrade=temperature-273.15

  print,'Time' 
  print,time[0:9]  
  Print, 'Latitude'
  Print, latitude[0:9]
  Print, 'Longitude'
  Print, longitude[0:9]
  print,'Temperature'
  print, temperature[0:9]  
  Print, 'Centigrade'
  Print, Centigrade[0:9]

;ENDIF

RETURN
END  

This works perfectly. My second Pro is as follows:-

PRO Change_Kelvin_to_Cent,Temperature

;+ This programme take the temperature from the NETCDF file and converts 
;   to Centigrade
;Output 
;  The Month Mean Temperature in Centigrade
;  Must have read ncdf1 in the directory run first
;  
;  -
COMPILE_OPt IDL2

infile='D:/Rwork/dataset/monthly_mean/version_2c/air.2m.mon.mean.nc'

read_netcdf1, infile, Temperature                



Centigrade = Temperature-273.15

print,'Centigrade'
print,Centigrade[0:9]

RETURN
END

This also works I am being instructed to call the variable "Temperature" from the first PRO to calculate the Temperature in the second PRO without the command line

read_netcdf1, infile, Temperature

I cannot get this to work. Can anybody advise and help me out of this problem please

Answer 1

I was misinformed . it can not be done. You must have the "read_netcdf1, infile, Temperature" piece of code. Although Temperature can be any tag because it the position it is in not the wording. i hope this makes sence