Why does plot using contourf take so long to generate and print?

I am reading in different files that have 750 x 500 data points. One type is amplitude data of uint8, converted to voltage (double). The other is tof (seconds) of int32. For the int32, I do not need the entire range of data, so I convert it to single and nanoseconds. The time (int32) version takes 4+ mminutes. I'm also not sure why the byte size of the cs array is almost 3 MB. I would have thought it to be half that. Any insight would be greatly appreciated. Below are the command line outputs:

MATLAB Version: 8.2.0.701 (R2013b)

>> read_tof_cscansC

'C:\ODIS_DATA\C9-2ML_7T8\Raw_Brd0_Ml2_THRE.xml'

1.9552 seconds: Read in data and created subplot

123.82 seconds: finished contourf

130.5659 seconds: colorbar

135.1009 seconds: Title

C9-2ML_7T8_THRE.jpg has been saved.

259.0069 seconds: Saved jpg and finished execution

>> clear >> read_cscans_wfmsC

    'C:\ODIS_DATA\C9-2ML_7T8\Raw_Brd0_Ml2_PTP.xml'

2.1172 seconds: Read in data and created subplot

13.2042 seconds: finished contourf

14.0325 seconds: colorbar

14.5849 seconds: Title and wfm locations

     C9-2ML_7T8.jpg has been saved.

29.4749 seconds: Saved jpg and finished execution

>> clear >> memory

Maximum possible array: 27785 MB (2.914e+10 bytes) *

Memory available for all arrays: 27785 MB (2.914e+10 bytes) *

Memory used by MATLAB: 1131 MB (1.186e+09 bytes)

Physical Memory (RAM): 16374 MB (1.717e+10 bytes)

• Limited by System Memory (physical + swap file) available.

>>whos cs

Name        Size               Bytes  Class     Attributes

cs        499x751            2997992  double              
>>

[José-Luis]

You could try converting everything to double first and then do your plotting.