archstevej

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14 years, 32 days

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These are replies submitted by archstevej

@archstevej 

Got this error also, when going line by line.

Error, (in Column) invalid input: member received A[1, 1], which is not valid for its 2nd argument, s

 

@Carl Love Thanks for the response. But I am getting this error.

 

Error, invalid input: ExportMatrix expects its 2nd argument, M, to be of type {Matrix, list(Matrix)}, but received A[2, 1][() .. (), [Column(DesiredOrder)]]

Great, thanks!

Great, thanks!

@gkokovidis Yes, that is one way. But, I have many calculations that I would like to be able to go back to later and adjust without having to reparameterize everything. Or even to make adjustments to existing plots, it would be nice to have the results stored somewhere.

 

I tried 

But, when I called it back the error is Error, (in plots/odeplot) input is not a valid dsolve/numeric solution


@gkokovidis Yes, that is one way. But, I have many calculations that I would like to be able to go back to later and adjust without having to reparameterize everything. Or even to make adjustments to existing plots, it would be nice to have the results stored somewhere.

 

I tried 

But, when I called it back the error is Error, (in plots/odeplot) input is not a valid dsolve/numeric solution


Thanks, this helps. I think what I really need is to save the results, or save a plot, and then when I get the new plot I call that file and add it. Is this possible? There are some manual changes I need to make each time I adjust my parameters, so it helps to restart, which clears out the previous plot.

 

Thanks,

Steve

Thanks, this helps. I think what I really need is to save the results, or save a plot, and then when I get the new plot I call that file and add it. Is this possible? There are some manual changes I need to make each time I adjust my parameters, so it helps to restart, which clears out the previous plot.

 

Thanks,

Steve

Ah yes, thanks. I just couldn't find it!


 

Thanks for the post!

Thanks for the post!

Okay, so if there is an equilibrium at some point in time, does it really matter from what direction I get there?  If I run time backwards, starting from the "ending points" , will the dynamics of my problem still be the same? I mean, will the signs of the partials still hold? For example, in my water pumping problem, costs increase as more water is pumped. If I run time backwards, I am still saying costs increase as water is pumped. The only difference is that in one case pumping decreases over time (to the equilibrium), whereas the other case pumping increases over time to a disequilibrium. As it stands now, when I run the problem forward in time pumping increases to infinity. This is completely unrealistic. However, if I put the negative sign, it goes to a nice equilibrium. I am trying to figure out if this makes any sense!

 

Thanks,

Steve

 

 

 

 

Okay, so if there is an equilibrium at some point in time, does it really matter from what direction I get there?  If I run time backwards, starting from the "ending points" , will the dynamics of my problem still be the same? I mean, will the signs of the partials still hold? For example, in my water pumping problem, costs increase as more water is pumped. If I run time backwards, I am still saying costs increase as water is pumped. The only difference is that in one case pumping decreases over time (to the equilibrium), whereas the other case pumping increases over time to a disequilibrium. As it stands now, when I run the problem forward in time pumping increases to infinity. This is completely unrealistic. However, if I put the negative sign, it goes to a nice equilibrium. I am trying to figure out if this makes any sense!

 

Thanks,

Steve

 

 

 

 

Okay, maybe I do not understand the process enough. I am following a paper that solves this ODE system. But, I only get their result when I put the negative sign in front of the second equation. When I don't put the negative sign, I see plots that basically go out to infinity. Any idea what could be going on here?

 

Thanks,

Steve 

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