| Re: Add one column based on the data in another column [message #55465] |
Wed, 22 August 2007 05:20 |
Conor
Messages: 138
Registered: February 2007
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Senior Member |
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On Aug 22, 5:08 am, DirtyHarry <kim20...@gmail.com> wrote:
> G'day, Everyone!
>
> I have this data file. This was summarized from bigger file for test
> simulation.
>
> aaa.txt
> 01 -999.9
> 02 -999.9
> 03 -999.9
> 04 0.13
> 05 -999.9
> 06 -999.9
> 07 0.17
> 08 -999.9
> 09 -999.9
> 10 -999.9
> 11 -999.9
> 12 -999.9
> 13 -999.9
> 14 -999.9
> 15 -999.9
>
> I am making another column based on 2nd column with these criteria.
> 1) All five lines should have the same value.
> 2) This value is come from 2nd column and should be 0 < value <
> 1.
> 3) If no value is in this range, (i.e. 11~15th lines above), just copy
> the values from 2nd column.
>
> This is my target array.
>
> 01 -999.9 0.13
> 02 -999.9 0.13
> 03 -999.9 0.13
> 04 0.13 0.13
> 05 -999.9 0.13
> 06 -999.9 0.17
> 07 0.17 0.17
> 08 -999.9 0.17
> 09 -999.9 0.17
> 10 -999.9 0.17
> 11 -999.9 -999.9
> 12 -999.9 -999.9
> 13 -999.9 -999.9
> 14 -999.9 -999.9
> 15 -999.9 -999.9
>
> To get this array, I coded as follows. However, something must be
> wrong so far. Please take a look and give me any suggestions. Thanks.
>
> pro albedo_final
> close, /all
> data1 = 'D:\MODIS_ALL\aaa.txt'
> num_data = file_lines(data1)
> albedo_arr = fltarr(2, num_data)
> albedo_fin = fltarr(3, num_data)
> albedo_OK = 0.0
>
> openr, 2, data1
> readf, 2, albedo_arr
> close, 2
> c1 = 0
>
> openw, 1, 'bbb.txt'
> for i= 0, num_data-1 do begin
>
> dd = 5*(c1+1) +1
> if albedo_arr[0, i] lt DD then begin
> if (albedo_arr[1,i] gt 0 and albedo_arr[1,i] lt 1) then
> begin
> albedo_OK = albedo_arr[1,i]
> print, albedo_OK
> endif
> albedo_fin[0:1, i] = albedo_arr[0:1, i]
> albedo_fin[2, i] = albedo_OK
>
> endif
> c1 = c1+1
> endfor
> print, albedo_fin
> ;printf, 1, albedo_fin
> ;close, 1
> print, " It's done!"
> end
>
> This is the last result.
>
> 1.00000 -999.900 0.000000
> 2.00000 -999.900 0.000000
> 3.00000 -999.900 0.000000
> 4.00000 0.130000 0.130000
> 5.00000 -999.900 0.130000
> 6.00000 -999.900 0.130000
> 7.00000 0.170000 0.170000
> 8.00000 -999.900 0.170000
> 9.00000 -999.900 0.170000
> 10.0000 -999.900 0.170000
> 11.0000 -999.900 0.170000
> 12.0000 -999.900 0.170000
> 13.0000 -999.900 0.170000
> 14.0000 -999.900 0.170000
> 15.0000 -999.900 0.170000
The problem is that your algorith is all wrong. Your program is
working fine, it's just doing the wrong thing. What it is doing is
that it is always writing out the albedo_ok variable to the third
column. Initially, the albedo_ok array has the value '0.0', which is
why this is outputted to the first 3 lines. Then, the albedo_ok value
changes only when you find a column with good data. When you do find
such a value, then the albedo_ok value changes and that is printed out
until you find another good value. So for instance if you had this
file:
1 -999
2 -999
3 0.18
4 -999
5 0.16
6 0.84
7 0.95
you would get this output:
1 -999 0.00
2 -999 0.00
3 0.18 0.18
4 -999 0.18
5 0.16 0.16
6 0.84 0.84
7 0.95 0.95
The problem is that you need to process and output five rows at a
time, you can't do them one at a time like you are doing now. What
you need to do is read in five lines at one time and compare the
values of the second column for all five lines. Then, you either
extract the one good value for output or you set the output to be
-999.9. Once you've figured out what you want to output, you output
all five lines at once and output the same value to the third column
for each line.
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