www.neuron.yale.edu

So I went to create a new model. I already had nrn7.1 but I thought I should install the new version. I did not delete the old one. Installation appeared to go fine.

On the desktop I made the folder I was going to work in "TC1" and within that folder I put a folder "cells" which was going to containing the geometry of the cells I was going to work on.

I created my .hoc file. (mosinit.hoc) in the folder "TC1". And in the folder "cells" I placed tc200.geo

mosinit.hoc contains two lines I was sure this morning, this gave no errors.

I changed the way I was opening .hoc files, so that when I doubled clicked on them, they were opened in a code editor. Now I am dragging and dropping the .hoc file onto the nrngui shortcut to open them.

However, now I get the error. I have read that xopen and load_file both check "$HOC_LIBRARY_PATH" i.e. they start from the directory TC1. Is this not correct?

I am not 100% sure that changing how I open the files is the problem, but it seems to be the only thing it could be. I tried to fix this problem by reinstalling nrn7.2 however, it does reset the file handling.
I'm pulling my hair our! How do I open the geometry file in a way such that I can create a portable directory?

I might also add that when I right click on the mosinit.hoc file, and tell it to run with neuron.exe if I perform getcwd() I get... On the other hand, if I drag and drop the mosinit.hoc onto the neurongui shortcut, I get I assume this is where the issue is coming from. Any ideas on why the working directory isn't being set to where the mosinit file is?

I can get around the issue by using However, this does not load any of the mechanisms...

Bill Connelly wrote:I already had nrn7.1 but I thought I should install the new version. I did not delete the old one. Installation appeared to go fine.

Under MSWin it has always been advised to uninstall a previous version (via the NEURON program group's uninstaller) before installing a new version. I'd be concerned about MSWin's registry settings getting messed up. If you are able to launch and run the new version's neurondemo, maybe there isn't a problem with your new installation--but I'd bet dollars to donuts that the old one has a few punctures.

I changed the way I was opening .hoc files, so that when I doubled clicked on them, they were opened in a code editor.
Now I am dragging and dropping the .hoc file onto the nrngui shortcut to open them.

However, now I get the error.
. . .

Code: Select all

nrniv: Can't open  cells/tc200.geo
 in /cygdrive/C/Users/Bill/Desktop/TC1/mosinit.hoc near line 2
 xopen("cells/tc200.geo")
                         ^
xopen("cells/tc200.geo"        )

Sounds like dragging and dropping the mosinit.hoc file isn't setting the current working directory to /cygdrive/C/Users/Bill/Desktop/TC1

I have read that xopen and load_file both check "$HOC_LIBRARY_PATH" i.e. they start from the directory TC1.

No, $HOC_LIBRARY_PATH is an environment variable that won't even exist unless you tell MSWin that it should and what it should contain. And if you rely on $HOC_LIBRARY_PATH for this particular project, you'd have to change it in order for drag & drop to work for a different project whose files are in a different folder on your desktop or anywhere else.

Try adding a third line to your mosinit.hoc so it readsand see if that helps.

The more I think about it, the less I like the solution I proposed. The chief problem is that your code won't work if you move it to another directory or try it on a different machine. None of this happens if you configure Windows to launch NEURON when you double click on a hoc file, and use drag and drop to open your hoc files in a text editor; I put a shortcut to my favorite text editor right on the desktop for that very purpose.

Yes, you're absolutely right Ted. I've been moving the model around onto various different computers to try and improve speed and I'm dealing with just this issue. I can report that by re-associating the files with neuron.exe the problem goes away. Strange that drag and dropping doesn't do the same thing.

Also, just in case anyone is stuck in a situation the way I was, you also need to follow up with nrn_load_dll("nrnmech.dll") after you chdir("/cygdrive/C/Users/Bill/Desktop/TC2/")