gnuplot-info

[Gnuplot-info] parse error in reading newline character from input redirected from awk

[baalkikhaal <col...@gm...>]

on doing

plot "< awk '{if (($2 == 26) && ($3 == 160))  printf("%.2f    %.8f ",$1,$6 *
4/exp(log($1)*3))}' < coordinates.dat " using 1:2 wi li title "26"

i get

line 21: invalid character \

but in shell on doing 

awk '{if (($2 == 26) && ($3 == 160))  printf("%.2f    %.8f ",$1,$6 *
4/exp(log($1)*3))}' < coordinates.dat

it is working fine....

what is the possible source of error?
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Re: [Gnuplot-info] parse error in reading newline character from input redirected from awk

[Hans-Bernhard B. <HBB...@t-...>]

baalkikhaal wrote:
> on doing
> 
> plot "< awk '{if (($2 == 26) && ($3 == 160))  printf("%.2f    %.8f ",$1,$6 *
> 4/exp(log($1)*3))}' < coordinates.dat " using 1:2 wi li title "26"

The second '<' doesn't serve much of a purpose, so you may want to drop it.

And you'll want to re-think the quoting.  You have two pairs of "double 
quotes" which you probably want nested, but they're not.

Re: [Gnuplot-info] parse error in reading newline character from input redirected from awk

[sreekar g. <col...@gm...>]

sorry for posting the wrong data. the problem was with

plot "< awk '{if (($2 == 26) && ($3 == 160))  printf("%.2f    %.8f* \n *",$1,$6
*
4/exp(log($1)*3))}' < coordinates.dat " using 1:2 wi li title "26"

and the *error* is
 invalid character \

i would be grateful for any help

sincerely,
sreekar
india


2009/9/26 Hans-Bernhard Bröker <HBB...@t-...>

> baalkikhaal wrote:
>
>> on doing
>>
>> plot "< awk '{if (($2 == 26) && ($3 == 160))  printf("%.2f    %.8f ",$1,$6
>> *
>> 4/exp(log($1)*3))}' < coordinates.dat " using 1:2 wi li title "26"
>>
>
> The second '<' doesn't serve much of a purpose, so you may want to drop it.
>
> And you'll want to re-think the quoting.  You have two pairs of "double
> quotes" which you probably want nested, but they're not.
>
>
>


-- 
Sreekar Guddeti

Re: [Gnuplot-info] parse error in reading newline character from input redirected from awk

[Hans-Bernhard B. <HBB...@t-...>]

sreekar guddeti wrote:
> sorry for posting the wrong data. the problem was with
> 
> plot "< awk '{if (($2 == 26) && ($3 == 160))  printf("%.2f    %.8f* \n *",$1,$6
> *
> 4/exp(log($1)*3))}' < coordinates.dat " using 1:2 wi li title "26"

That makes it even more obvious that the problem is with the quotes, and 
explains why you didn't have a problem using the same awk command in the 
shell: the outer pair of quotes doesn't appear in the shell command, and 
thus the problem with nested quotes doesn't apply.  The backslash it's 
complaining about is the one of the \n you've now put back in, and it 
gets complained about because to gnuplot's command-line parser, it 
appears outside any string.  Which it shouldn't.

You have to quote the inner "double quotes", and the backslash:

plot "< awk '{if (($2 == 26) && ($3 == 160)) printf(\"%.2f %.8f\\n\", 
$1,$6*4/exp(log($1)*3))}' coordinates.dat " using 1:2 wi li title "26"

[all on a single line]

OTOH, I would suggest to drop awk and instead do it all in gnuplot:

    plot 'coordinates.dat' u (($2==26)&&($3==160)?$1:0/0):($6*4/($1**3))