# Fortran how to read double precision data in input text file to real no output text file **URL:** \ **Category:** Uncategorized\ **Created:** [September 25, 2021, 2:19am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930 "2021-09-25T02:19:58Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![josanps](https://avatars.discourse-cdn.com/v4/letter/j/ecb155/32.png) [@josanps](https://fortran-lang.discourse.group/u/josanps)\ **Post date:** [September 25, 2021, 2:19am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930/1 "2021-09-25T02:19:58Z")
INPUT TEXT FILE | time | isobaric | lat | lon | u-component\_of\_wind\_isobaric | | --- | --- | --- | --- | --- | | 0.0 | 10000.0 | 0.0 | 45.0 | 2.3169289 | | 0.0 | 10000.0 | 0.0 | 45.119998931884766 | 2.4106789 | | 0.0 | 10000.0 | 0.11999999731779099 | 45.0 | 2.2231789 | | 0.0 | 10000.0 | 0.11999999731779099 | 45.119998931884766 | 2.3481789 | | 0.0 | 10000.0 | 0.11999999731779099 | 45.2400016784668 | 2.3169289 | | 0.0 | 100000.0 | 0.11999999731779099 | 45.36000061035156 | -2.984314 | | 0.0 | 100000.0 | 0.11999999731779099 | 45.47999954223633 | -2.734314 | | 0.0 | 100000.0 | 0.0 | 45.0 | -2.890564 | | 0.0 | 100000.0 | 0.0 | 45.119998931884766 | -2.781189 | OUT PUT TEXT FILE CONTENT time isobaric lat lon u-component\_of\_wind\_isobaric 0.0 10000.00 0.00 45.00 2.32 ``` 0.0 10000.00 0.00 45.84 1.91 0.0 10000.00 0.00 46.80 2.91 ``` ---
**Author:** ![Beliavsky](https://avatars.discourse-cdn.com/v4/letter/b/ba8739/32.png) [@Beliavsky](https://fortran-lang.discourse.group/u/Beliavsky)\ **Post date:** [September 25, 2021, 2:41am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930/2 "2021-09-25T02:41:35Z")
Welcome to the forum. Could you show your code where you tried to `open` the text file, `read` it, and then `write` it, and say what specific problem you encountered? If you have an array of character strings called `words(:)` you can read all of them with `read (input_unit,*) words` You can read one row of a matrix `x(:,:)` with `read (input_unit,*) x(irow,:)` and write it in a similar manner. If the output for numbers should have one decimal point for the first column and two for the remaining, you could do something like `write (ouput_unit,"(f0.1,*(1x,f0.2))") x(irow,:)` ---
**Author:** ![josanps](https://avatars.discourse-cdn.com/v4/letter/j/ecb155/32.png) [@josanps](https://fortran-lang.discourse.group/u/josanps)\ **Post date:** [September 25, 2021, 8:39am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930/3 "2021-09-25T08:39:23Z")
I Thank you i put the code in fortran 95 silver frost version as given below and it compiles ok. But run time error format/data mismatch error shows line 25 error that is `WRITE(14,"(F0.1,5(1X,F0.2))")X(IROW,:)` The format string is only valid if `X` is declared `real`. In your code it is an array of type `character`. Here is a program that works with gfortran or Intel Fortran that reads the data into an array and writes it to a file. ```auto program main implicit none integer, parameter :: nfields = 5, max_rows = 1000, dp = kind(1.0d0) character (len=1000) :: title ! use a long length -- it will be trimmed later real(kind=dp) :: x(max_rows, nfields) integer :: ierr,irow, in_unit, out_unit open (newunit=in_unit, file = "test4.txt", action = "read", status = "old") open (newunit=out_unit, file = "result4.txt", action = "write", status = "replace") read (in_unit,"(a)") title write (out_unit,"(a)") trim(title) do irow=1,max_rows read (in_unit,*,iostat=ierr) x(irow,:) if (ierr /= 0) exit write (out_unit,"(f10.1,*(1x,f10.2))") x(irow,:) end do end program main ``` The output file contains ```auto time isobaric lat lon u-component_of_wind_isobaric 0.0 10000.00 0.00 45.00 2.32 0.0 10000.00 0.00 45.12 2.41 0.0 10000.00 0.12 45.00 2.22 0.0 10000.00 0.12 45.12 2.35 0.0 10000.00 0.12 45.24 2.32 0.0 100000.00 0.12 45.36 -2.98 0.0 100000.00 0.12 45.48 -2.73 0.0 100000.00 0.00 45.00 -2.89 0.0 100000.00 0.00 45.12 -2.78 ``` If you don’t need to store all the data the program could be simplified. ---
**Author:** ![josanps](https://avatars.discourse-cdn.com/v4/letter/j/ecb155/32.png) [@josanps](https://fortran-lang.discourse.group/u/josanps)\ **Post date:** [September 26, 2021, 6:38am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930/4 "2021-09-26T06:38:52Z")
Thank you once again for wonderful help The program works well in fortran95 silver frost version as given below ```auto PROGRAM MAIN IMPLICIT NONE INTEGER, PARAMETER :: NFIELDS =5, MAX_ROWS =1000, DP = KIND(1.0D0) CHARACTER (LEN =1000) :: TITLE REAL(KIND = DP) :: X(MAX_ROWS,NFIELDS) INTEGER :: IERR,IROW, IN_UNIT=10, OUT_UNIT =14 OPEN ( IN_UNIT, FILE="TEST4.TXT", ACTION = "READ", STATUS = "OLD") OPEN ( OUT_UNIT, FILE="RESULT4.TXT", ACTION = "WRITE", STATUS = "REPLACE") READ (IN_UNIT,"(A)")TITLE WRITE (OUT_UNIT,"(A)")TRIM(TITLE) DO IROW = 1,MAX_ROWS READ(IN_UNIT,*,IOSTAT = IERR) X(IROW,:) IF (IERR /=0 ) EXIT IF (IROW .EQ. 1 .OR. mod(IROW,8) .EQ. 0) THEN WRITE (OUT_UNIT, "(F10.1,5(1X,F10.2))") X(IROW,:) END IF END DO CLOSE(IN_UNIT) CLOSE(OUT_UNIT) END PROGRAM MAIN ``` ---
**Author:** ![Beliavsky](https://avatars.discourse-cdn.com/v4/letter/b/ba8739/32.png) [@Beliavsky](https://fortran-lang.discourse.group/u/Beliavsky)\ **Post date:** [September 26, 2021, 11:21am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930/5 "2021-09-26T11:21:19Z")
> [@josanps](#): > > Thank you once again for wonderful help > The program works well in fortran95 silver frost version > as given below I’m glad it worked. I suggest writing code in lower case for legibility. Some Fortran best practices are listed [here](https://fortran-lang.org/learn/best_practices). You probably replaced the `newunit=in_unit` with setting `in_unit` to a `parameter` because Silverfrost does not support `newunit`, which was not in Fortran 95. Silverfrost is fine for Fortran 95, but [gfortran](https://fortran-lang.org/learn/os_setup) and Intel Fortran are both free for Windows and support more recent Fortran standards. I suggest using one of them as your main compiler. A posting tip is that using the \ icon in the toolbar at the top formats the code in a message. ---
**Author:** ![josanps](https://avatars.discourse-cdn.com/v4/letter/j/ecb155/32.png) [@josanps](https://fortran-lang.discourse.group/u/josanps)\ **Post date:** [October 4, 2021, 1:37am UTC](https://fortran-lang.discourse.group/t/fortran-how-to-read-double-precision-data-in-input-text-file-to-real-no-output-text-file/1930/6 "2021-10-04T01:37:15Z")
`Hello , help me to write find the values for the following differential equation -1/g ∫\_(Y\_1)^(Y\_2)▒∫\_(p\_1)^(p\_2)▒〖( u^2)(\_X\_1^(X\_2))dy dp 〗 ```auto `Hello , help me to write find the values for the following differential equation -1/g ∫_(Y_1)^(Y_2)▒∫_(p_1)^(p_2)▒〖( u^2)(_X_1^(X_2))dy dp 〗 -1/g ∫_(Y_1)^(Y_2)▒∫_(p_1)^(p_2)▒〖( u^2)(_X_1^(X_2))dy dp 〗 With values dy=0.12 dp =p(n+1)-p(n) g=9.806 Where (x,y) is same grid points of a 3 dimensional rectangular box (1,1),(111,111),(222,222)…(888,888) X Y P T U 1 1 1 1 1.32 2 2 1 1 2.32 - - - - - 110 110 1 1 1.25 111 111 1 1 3.47 112 112 2 1 -25.45 - - - - - 222 222 3 1 3.34 - - - - - 333 333 4 1 -3.21 - - - - - 888 888 8 1 -4.20 --- u is given pr(1)=100(.ie. p=1) pr(2)=200(ie p=2,3,4,..8) PR(1)= 100.;PR(2)= 200.;PR(3)=300.;PR(4)=500.;PR(5)=700.;PR(6)=800.;PR(7)=900.;PR(8)=1000. long =111 or total 888 lat =111 or 888 day=1, dyy=0.12,phi1=5.04 subroutine ewflx(u,pr,long,lat,day,dyy,phi1,rmewfl) --- return;end ``` Thank you for your advice