gnuplot-info — For questions and discussion about gnuplot

Re: [Gnuplot-info] range of fitted variable

[Patrick D. <pd...@gm...>]

Hello,

I am not sure that it is a helfull response.
Even with Marquardt-Levenberg method, you can constrain parameters.
Anyway, you can always does it in the function, and put the constrains here
since conditional statement are accepted.

Regards.

> Subject: Re: [Gnuplot-info] range of fitted variable
>
> --- pdupre
> > Hello,
> >
> > Can I set a range to the fitted variable ?
> > An option could be to set a if (condition) in the fitting function. Is it possible?
> >
> > Thanks
> >
>
> fit of gnuplot use Marquardt-Levenberg method.
> Marquardt-Levenberg method is a uncostrained method. You cannot set bounds of parameters.
>
> Tatsuro
>
>

Re: [Gnuplot-info] range of fitted variable

[Tatsuro M. <tma...@ya...>]

--- pdupre
> Hello,
> 
> Can I set a range to the fitted variable ?
> An option could be to set a if (condition) in the fitting function. Is it possible?
> 
> Thanks
> 

fit of gnuplot use Marquardt-Levenberg method.
Marquardt-Levenberg method is a uncostrained method. You cannot set bounds of parameters.

Tatsuro

[Gnuplot-info] range of fitted variable

[Patrick D. <pd...@gm...>]

Hello,

Can I set a range to the fitted variable ?
An option could be to set a if (condition) in the fitting function. Is it possible?

Thanks

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

Re: [Gnuplot-info] subroutine

[Tatsuro M. <tma...@ya...>]

-- pdupre
> Hello,
> 
> Can I make a subroutine like
> sub F () {
> list of gnuplot calls ;
> }
> 
> Thank.


You cannot do it in a script file.
You can call other script files with arguments by  
call command.


see  

help call

Tatsuro

[Gnuplot-info] subroutine

[Patrick D. <pd...@gm...>]

Hello,

Can I make a subroutine like
sub F () {
list of gnuplot calls ;
}

Thank.

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

Re: [Gnuplot-info] gnuplot error message "skipping data file with no valid points - x range is invalid"

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

Am 24.06.2019 um 23:04 schrieb aflint414:
> so i was attempting to make a simple graph. i made the graph successfully but
> it was only when i attempted to export it per some website's instructions
> that things started going south.

That's because ypu either mis-applied those instructions, or they were
horrificially bad.

> gnuplot> set output "file.dat"
> gnuplot> replot
>          warning: Skipping data file with no valid points
> 
> gnuplot> plot "file.dat" using 1:2 pt 7 ps 2

You've now named the _same_ file as text data input, _and_ GIF-format
output.  That cannot possibly do what you wanted.

Re: [Gnuplot-info] gnuplot error message "skipping data file with no valid points - x range is invalid"

[Tatsuro M. <tma...@ya...>]

--- aflint414
> so i was attempting to make a simple graph. i made the graph successfully but
> it was only when i attempted to export it per some website's instructions
> that things started going south.
> this is what i submitted and what was output:
> 
> gnuplot> set title "title"
> gnuplot> set term gif
> 
> Terminal type is now 'gif'
> Options are 'nocrop enhanced size 640,480 font "arial,12.0" '
> gnuplot> set output "file.dat"
> gnuplot> replot
>          warning: Skipping data file with no valid points
> 
> gnuplot> plot "file.dat" using 1:2 pt 7 ps 2
>                                               ^
>          x range is invalid
> 
> gnuplot> replot
>          warning: Skipping data file with no valid points
> 
> gnuplot> plot "file.dat" using 1:2 pt 7 ps 2
>                                               ^
>          x range is invalid
> 
> and when i opened nano in another window and attempted to open said data
> file, there was nothing in it anymore. can someone explain to me what has
> happened/how to fix it? it's for work and very urgent. much appreciated!
> 
> it should be said that i was able to export via another method but i am
> still having the issues with not being able to reopen/manipulate the old
> plot anymore.
> 
> 
> 
please show initial plot command with which you got a successful result.

BTW,
set output (file name)

gives a gif image file for your case but not gives data.

Tatsuro

[Gnuplot-info] gnuplot error message "skipping data file with no valid points - x range is invalid"

[aflint414 <afl...@gm...>]

so i was attempting to make a simple graph. i made the graph successfully but
it was only when i attempted to export it per some website's instructions
that things started going south.
this is what i submitted and what was output:

gnuplot> set title "title"
gnuplot> set term gif

Terminal type is now 'gif'
Options are 'nocrop enhanced size 640,480 font "arial,12.0" '
gnuplot> set output "file.dat"
gnuplot> replot
         warning: Skipping data file with no valid points

gnuplot> plot "file.dat" using 1:2 pt 7 ps 2
                                              ^
         x range is invalid

gnuplot> replot
         warning: Skipping data file with no valid points

gnuplot> plot "file.dat" using 1:2 pt 7 ps 2
                                              ^
         x range is invalid

and when i opened nano in another window and attempted to open said data
file, there was nothing in it anymore. can someone explain to me what has
happened/how to fix it? it's for work and very urgent. much appreciated!

it should be said that i was able to export via another method but i am
still having the issues with not being able to reopen/manipulate the old
plot anymore.



--
Sent from: http://gnuplot.10905.n7.nabble.com/Gnuplot-User-f3.html

Re: [Gnuplot-info] fit by varying the data

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

Am 19.06.2019 um 00:36 schrieb Patrick Dupre:

> I do not have a 3D cloud of points, just 2 sets of points (same length) with the
> same x, 

Whether you admit it or not: that _is_ a cloud of points in 3D space.
It's just represented a bit disjointedly.

> I "just need" to minimize the sum  of the square between a given function
> and a set of data (which depend on 1 parameter).

And that's, again, where this fails to make sense.  If something depends
on a parameter, it's not a set of data --- it's a function of said
parameter, and the actual data.  Just like it's normal for the model
function of a fit.

Your linear combination of y1 and y2 is a projection of the (y1,y2)
plane onto a straight line rotated at angle \theta.  Then you compare
this projected value to a function depending on x.  In the end, this
means the function you need to minimize would actually be one of three
variables, something like

	projection(theta; y1, y2) - function(a, x0; x) = min!

or possibly

	projection^2(theta; y1, y2) - function^2(a, x0; x) = min!

Re: [Gnuplot-info] fit by varying the data

[Patrick D. <pd...@gm...>]

Hello Hans,

It seems difficult to speak with you.
I do not have a 3D cloud of points, just 2 sets of points (same length) with the
same x, and I need to fit a linear combination of these y1 and y2 with a
parameter (here theta) to fit the combination with a know (and simple) function
(which has 2 parameters to adjust).
Indeed, I can currently solve my problem visually by using gnuplot.
I "just need" to minimize the sum  of the square between a given function
and a set of data (which depend on 1 parameter).
Whatever are these data, they just have to be recalculated for each new fitted parameters
(actually for only one parameter).
Any minimization algorithm does that, except that in general, is does not have to recalculate
the dataset, but basically it is the same procedure.
I did it a thousand of times, but not with gnuplot, and I wanted to do
the same with gnuplot.

Please note that doing
(x=$1):
works perfectly well.
There is maybe other option, but I can also want to do (x=$1/1000):

When I said:

y(x) = $2 (x) *sin(theta) + $3 (x) *cos(theta)

it should have maybe said:
y(i) = $2 (i) *sin(theta) + $3 (i) *cos(theta)
where i is the index of the array, and assuming that $2 is a dataset
that I index with i.
Actually, I do not know how to said that with the words of gnuplot, but
if you tell me how to calculate
the minimum of (y(x) - f(x))^2 for 3 parameters, I shall be happy.
(x can be an index).

My Best.

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================


> Sent: Wednesday, June 19, 2019 at 12:01 AM
> From: "Hans-Bernhard Bröker" <HBB...@t-...>
> To: gnuplot <gnu...@li...>
> Subject: Re: [Gnuplot-info] fit by varying the data
>
> Am 18.06.2019 um 21:33 schrieb Patrick Dupre:
> > Sorry,
> > 
> > Why it does not make sense?
> 
> Because it doesn't.  Assigning data to 'x' makes no sense because that's
> what giving those data as the first "using" specifier already does, and
> because 'x is not available to be assigned.
> 
> > I need to fit 3 parameters,
> > x0, a and theta
> > by minimizing the sum of the square root:
> > The function depend only on x (and of the parameters, x0 and a)
> > while I have 2 sets of that $2 and $3 (which depend on the same 
> > x).
> > I only know a linear combination of this 2 sets that can be fitted
> > y(x) = $2 (x) *sin(theta) + $3 (x) *cos(theta)
> 
> No, you don't know that combination.  Which is why you're looking for it.
> 
> > There is no fundamental glitch.
> 
> I'm not convinced you've quite reached the point where you should be the
> sole judge on that.
> 
> > The 2 set of data are issue from the same experiment.
> > Typically, it is vector whose you want to fit the direction.
> 
> As given, no, it's not.  You have a cloud of points in 3D.  What you're
> trying to fit is, for all practical intents and purposes, a plane
> through that cloud.  Except that, for some reason, you want to express
> the orientation of that plane partially as an angle, partially as a slope.
> 
> And the easiest way of doing that may well be to turn things around:
> express $1 as a function of $2 and $3, and fit that.
> 
> fit (cos(theta)*x+sin(theta)*y)/a + x0 'data' using 2:3:1 via a, x0, theta
> 
> 
> > I need to re-read the datasets which are stored in $DATA
> 
> No, you don't.  You need to re-format your problem statement to
> eliminate that apparent need.
> 
> 
> _______________________________________________
> gnuplot-info mailing list
> gnu...@li...
> Membership management via: https://lists.sourceforge.net/lists/listinfo/gnuplot-info
>

Re: [Gnuplot-info] fit by varying the data

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

Am 18.06.2019 um 21:33 schrieb Patrick Dupre:
> Sorry,
> 
> Why it does not make sense?

Because it doesn't.  Assigning data to 'x' makes no sense because that's
what giving those data as the first "using" specifier already does, and
because 'x is not available to be assigned.

> I need to fit 3 parameters,
> x0, a and theta
> by minimizing the sum of the square root:
> The function depend only on x (and of the parameters, x0 and a)
> while I have 2 sets of that $2 and $3 (which depend on the same 
> x).
> I only know a linear combination of this 2 sets that can be fitted
> y(x) = $2 (x) *sin(theta) + $3 (x) *cos(theta)

No, you don't know that combination.  Which is why you're looking for it.

> There is no fundamental glitch.

I'm not convinced you've quite reached the point where you should be the
sole judge on that.

> The 2 set of data are issue from the same experiment.
> Typically, it is vector whose you want to fit the direction.

As given, no, it's not.  You have a cloud of points in 3D.  What you're
trying to fit is, for all practical intents and purposes, a plane
through that cloud.  Except that, for some reason, you want to express
the orientation of that plane partially as an angle, partially as a slope.

And the easiest way of doing that may well be to turn things around:
express $1 as a function of $2 and $3, and fit that.

fit (cos(theta)*x+sin(theta)*y)/a + x0 'data' using 2:3:1 via a, x0, theta


> I need to re-read the datasets which are stored in $DATA

No, you don't.  You need to re-format your problem statement to
eliminate that apparent need.

Re: [Gnuplot-info] fit by varying the data

[Patrick D. <pd...@gm...>]

Sorry,

Why it does not make sense?
I need to fit 3 parameters,
x0, a and theta
by minimizing the sum of the square root:
The function depend only on x (and of the parameters, x0 and a)
while I have 2 sets of that $2 and $3 (which depend on the same 
x).
I only know a linear combination of this 2 sets that can be fitted
y(x) = $2 (x) *sin(theta) + $3 (x) *cos(theta)
There is no fundamental glitch. The 2 set of data are issue from the same experiment.
Typically, it is vector whose you want to fit the direction.
This direction is optimum when one of the components varies linearly.
I just need to minimize \sum (y(x) - a*(x-x0))^2
I need to re-read the datasets which are stored in $DATA
Any minimization program can potentially do it.


===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================


> Sent: Tuesday, June 18, 2019 at 8:45 PM
> From: "Hans-Bernhard Bröker" <HBB...@t-...>
> To: "Patrick Dupre" <pd...@gm...>, gnuplot <gnu...@li...>
> Subject: Re: [Gnuplot-info] fit by varying the data
>
> Am 18.06.2019 um 18:53 schrieb Patrick Dupre:
> > Hello,
> > 
> > Can I do this:
> > fit a*(x-x0) $DATA u (x=$1):($2*sin(theta)+$3*cos(theta)) via x0,a,theta
>                         ^^^^
> 
> That assignment operation makes no sense at all.
> 
> And no, you can't do that.  The parameters have to influence the
> _function_, not the data.  You really wouldn't want to re-read the
> entire dataset on every iteration of 'fit', just to update the effect of
> parameters on the data.
> 
>

Re: [Gnuplot-info] fit by varying the data

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

Am 18.06.2019 um 18:53 schrieb Patrick Dupre:
> Hello,
> 
> Can I do this:
> fit a*(x-x0) $DATA u (x=$1):($2*sin(theta)+$3*cos(theta)) via x0,a,theta
                        ^^^^

That assignment operation makes no sense at all.

And no, you can't do that.  The parameters have to influence the
_function_, not the data.  You really wouldn't want to re-read the
entire dataset on every iteration of 'fit', just to update the effect of
parameters on the data.

[Gnuplot-info] fit by varying the data

[Patrick D. <pd...@gm...>]

Hello,

Can I do this:
fit a*(x-x0) $DATA u (x=$1):($2*sin(theta)+$3*cos(theta)) via x0,a,theta

Actually it fails if I let theta vary.
Can I do something similar?

Thank

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

Re: [Gnuplot-info] pass table to awk

[Patrick D. <pd...@gm...>]

A way to save my issue would probably to generate a table with 3 columns,
But I did not find a way to do so.

>
> Hello,
> 
> I have a variable (table)
> How can I pass it to awk?
> Thank
> 
> ===========================================================================
>  Patrick DUPRÉ                                 | | email: pd...@gm...
>  Laboratoire interdisciplinaire Carnot de Bourgogne
>  9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
>  Tel: +33 (0)380395988
> ===========================================================================
> 
> 
> 
> _______________________________________________
> gnuplot-info mailing list
> gnu...@li...
> Membership management via: https://lists.sourceforge.net/lists/listinfo/gnuplot-info
>

[Gnuplot-info] pass table to awk

[Patrick D. <pd...@gm...>]

Hello,

I have a variable (table)
How can I pass it to awk?
Thank

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

[Gnuplot-info] fit of 2 set of data

[Patrick D. <pd...@gm...>]

Hello,

I have 2 tables
$T1 and $T2
I would like to fit a function f(x) via var1 such the fitted data are:
cos(var1) * $T1 +  sin(var1) * T2

Is it possible?

Thank.

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

Re: [Gnuplot-info] Recover parameter of the previous fit

[Ethan A M. <eam...@gm...>]

On Monday, 27 May 2019 19:00:36 Patrick Dupre wrote:
> OK,
>  
> save fit 'save'
> should work,
>  
> How do I recover the parameters ?
> using via?
> I am not sure that I understand.

The inverse of "save" is "load"

	Ethan



>  
> Thank.
>  
> ===========================================================================
> Patrick DUPRÉ | | email: pd...@gm...
> Laboratoire interdisciplinaire Carnot de Bourgogne
> 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
> Tel: +33 (0)380395988
> ===========================================================================
>  
>  
> Sent: Monday, May 27, 2019 at 6:39 PM
> From: "Ethan A Merritt" <eam...@gm...>
> To: gnu...@li...
> Cc: "Patrick Dupre" <pd...@gm...>
> Subject: Re: [Gnuplot-info] Recover parameter of the previous fit
> On Monday, 27 May 2019 16:53:59 Patrick Dupre wrote:
> > Hello,
> >
> > Sometimes, the fit does not converge properly and we would like to recover
> > the parameters of the previous fit.
> > 1) it is possible?
> > 2) if not, how can I save the parameters of a fit and recall them later?
>  
> Does the "save fit" command not work for you?
> The intended use is:
>  
> fit ... #works
> save fit 'save.file'
> ...
> ... lots of stuff that may or may not have worked
> ...
> load 'save.file' # restore saved variables.
>  
>  
> Ethan
>  
>  
> --
> entia non sunt multiplicanda praeter necessitatem
> 

-- 
entia non sunt multiplicanda praeter necessitatem

Re: [Gnuplot-info] Recover parameter of the previous fit

[Ethan A M. <eam...@gm...>]

On Monday, 27 May 2019 16:53:59 Patrick Dupre wrote:
> Hello,
> 
> Sometimes, the fit does not converge properly and we would  like to recover
> the parameters of the previous fit.
> 1) it is possible?
> 2) if not, how can I save the parameters of a fit and recall them later?

Does the "save fit" command not work for you?
The intended use is:

fit ...    #works
save fit 'save.file'
...
...  lots of stuff that may or may not have worked
...
load 'save.file'   # restore saved variables.


	Ethan


-- 
entia non sunt multiplicanda praeter necessitatem

Re: [Gnuplot-info] Recover parameter of the previous fit

[Tatsuro M. <tma...@ya...>]

Let a be a fitting parameter.

a_save = a  

before fit.

Tatsuro

--- pdupre
> Hello,
> 
> Sometimes, the fit does not converge properly and we would  like to recover
> the parameters of the previous fit.
> 1) it is possible?
> 2) if not, how can I save the parameters of a fit and recall them later?
> 
> Thank.
> 
> ===========================================================================
>  Patrick DUPRÉ                                 | | email: pd...@gm...
>  Laboratoire interdisciplinaire Carnot de Bourgogne
>  9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
>  Tel: +33 (0)380395988
> ===========================================================================
> 
> 
> 
> _______________________________________________
> gnuplot-info mailing list
> gnu...@li...
> Membership management via: https://lists.sourceforge.net/lists/listinfo/gnuplot-info 

Re: [Gnuplot-info] paste + awk

[Patrick D. <pd...@gm...>]

OK,

Do not worry. Every thing is under control now.

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================


> Sent: Monday, May 27, 2019 at 5:43 PM
> From: "walter harms" <wh...@bf...>
> To: gnu...@li...
> Cc: "Patrick Dupre" <pd...@gm...>
> Subject: Re: [Gnuplot-info] paste + awk
>
> 
> 
> Am 24.05.2019 17:20, schrieb Patrick Dupre:
> > Hello,
> > 
> > I wanted to run such a command, but it does not work.
> > 
> > plot "< paste  . test.asc . |awk -F',' '(NR>1) {print ($1, $2)}' "
> > or
> > plot "< paste " . test.asc . "|awk -F',' '(NR>1) {print ($1, $2)}' "
> > 
> > Actually, I want to make a paste of 2 files, before awk 
> > Here I tried with 1 file
> > 
> 
> 
> this works for me:
> seq 5  -1 1 >f1
> seq 1 5 >f2
> 
> gnuplot> plot "< paste f2 f1" u 1:2 w l
> 
> re,
>  wh
>

[Gnuplot-info] multithread

[Patrick D. <pd...@gm...>]

Hello,

Is it possible to to run gnuplot with parallel option on multicore
systems?

Thank

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

[Gnuplot-info] Recover parameter of the previous fit

[Patrick D. <pd...@gm...>]

Hello,

Sometimes, the fit does not converge properly and we would  like to recover
the parameters of the previous fit.
1) it is possible?
2) if not, how can I save the parameters of a fit and recall them later?

Thank.

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

[Gnuplot-info] paste + awk

[Patrick D. <pd...@gm...>]

Hello,

I wanted to run such a command, but it does not work.

plot "< paste  . test.asc . |awk -F',' '(NR>1) {print ($1, $2)}' "
or
plot "< paste " . test.asc . "|awk -F',' '(NR>1) {print ($1, $2)}' "

Actually, I want to make a paste of 2 files, before awk 
Here I tried with 1 file

thank

===========================================================================
 Patrick DUPRÉ                                 | | email: pd...@gm...
 Laboratoire interdisciplinaire Carnot de Bourgogne
 9 Avenue Alain Savary, BP 47870, 21078 DIJON Cedex FRANCE
 Tel: +33 (0)380395988
===========================================================================

Re: [Gnuplot-info] Configurable FP precision (Re: accuracy in calculation)

[Nikita Z. <coo...@ma...>]

On Sat, 13 Apr 2019 05:33:27 -0700 (PDT)
David Lang <da...@la...> wrote:

> myh apologies, I got this mixed up with a different mailing list (for
> some reason I thought this was the grbl mailing list which runs on
> the arduino boards), so ignore my comment.
> 
> David Lang
> 
>   On Sat, 13 Apr 2019, Nikita Zlobin via gnuplot-info wrote:
> 

No probs :)