"every", "x range is invalid"

[Igor Kozlov]

Hello all!
I want to type only 2 line in the second block of my data file.
I use the following command:
plot "t1" every 1:1:1:1:1:1
^
x range is invalid.

I have already read help, several manuals and searched in google, but
cannot understand where is the mistake?

I attach the file "t1"
and
source code in Fortran 77, that generated this file
***********************************************************************
# BLOCK = 0

0.000000000000000 1.000000000000000

1.000000000000000 1.000000000000000

2.000000000000000 1.000000000000000

3.000000000000000 1.000000000000000

4.000000000000000 1.000000000000000

# BLOCK = 1

0.000000000000000 0.000000000000000

1.000000000000000 1.000000000000000

2.000000000000000 2.000000000000000

3.000000000000000 3.000000000000000

4.000000000000000 4.000000000000000

# BLOCK = 2

0.000000000000000 0.000000000000000

1.000000000000000 1.000000000000000

2.000000000000000 4.000000000000000

3.000000000000000 9.000000000000000

4.000000000000000 16.000000000000000

***********************************************************************
PROGRAM test
IMPLICIT NONE
INTEGER N_WRITE, N_OPEN_W
INTEGER I_BLOCK, I_LINE
CHARACTER ADR_FILE*200

ADR_FILE='/home/gnuplot/t1'

OPEN(UNIT=11,STATUS='UNKNOWN',FILE=ADR_FILE,
*ACCESS='SEQUENTIAL',FORM='FORMATTED',ERR=903,IOSTAT=N_OPEN_W,
*BLANK='NULL')

DO 2 I_BLOCK = 0,2

WRITE (UNIT=11,FMT=117,IOSTAT=N_WRITE,ERR=904) I_BLOCK
117 FORMAT ('# BLOCK = ',I1,/)

DO 1 I_LINE = 0,4

WRITE (UNIT=11,FMT=130,IOSTAT=N_WRITE,ERR=904)
*DBLE(I_LINE), DBLE(I_LINE)**DBLE(I_BLOCK)
130 FORMAT (' ',F18.15,' ',F18.15,/)

1 CONTINUE

WRITE (UNIT=11,FMT=120,IOSTAT=N_WRITE,ERR=904)
120 FORMAT (//,//)

2 CONTINUE

CLOSE(UNIT=11)

RETURN

903 PRINT *, 'ERROR = ', N_OPEN_W, 'OPENING OUT FILE'
RETURN
904 PRINT *, 'ERROR =', N_WRITE, 'WRITING TO OUT FILE'
RETURN

END

[Hans-Bernhard Bröker]

Igor Kozlov wrote:
> Hello all!
> I want to type only 2 line in the second block of my data file.
> I use the following command:
> plot "t1" every 1:1:1:1:1:1
> ^
> x range is invalid.

Your data file has way too many empty records (a.k.a. blank lines) to be
interpreted by gnuplot in the way you expect. In particular, this:

> # BLOCK = 0
>
> 0.000000000000000 1.000000000000000
>
> 1.000000000000000 1.000000000000000
>
> 2.000000000000000 1.000000000000000
>
> 3.000000000000000 1.000000000000000
>
> 4.000000000000000 1.000000000000000
>

is not one data block of 5 points, as you apparently intended. It's a
sequence of 5 blocks of one data point each, instead. Therefore there's
not a single data point that fits your "every" selection arguments, and
thus nothing to plot.