Joe,

I am back to my computer. If keeping the file in that directory is what you care about than just do the following:

NotebookEvaluate[NotebookDirectory[] <>"myfile.nb"]

This will execute the notebook contents and define all of its functions as if you opened it up manually and executed it in the kernel.

I still recommend packages. The way I do it is I develop the package in my "home" directory (so it is backed up and version controlled etc.). I install a COPY of the file into the $BaseDirectory/Applications. When I make improvements they are done on the home version of the file and then installed (usually manually by copying the file). If I have a really complicated package, I use eclipse with Wolfram Workbench installed because you can debug it and develop documentation for it. I hope this helps. If you need better instructions or an example, let me know.

Regards,

Neil

If keeping the file in that directory is what you care about than just do the following:

NotebookEvaluate[NotebookDirectory[] <>"myfile.nb"]

This is not a safe way to assemble paths because it assumes that NotebookDirectory[] returns a string ending in the path separator. When I tried it on my system, that was indeed the case. But can you trust it to always do this, for any directory, on any operating system, and with any version of Mathematica? Directory[] doesn't put a path separator at the end of its return value on my computer, therefore the above method wouldn't work with it.

Use this instead:

FileNameJoin[{NotebookDirectory[], "myfile.nb"}]

By the way, I notice that your example is a decibel conversion. If you want to send me your email address I will send you a Dropbox link to an application I developed called UnitsHelper. It has a generalized decibel conversion facility as well as routines to install reduced unit systems, such as geometric units or atomic units, as well as other nifty features.

It also has style sheets, palettes and documentation and thus illustrates a rather complete example of setting up an application in Mathematica.

My email is on my profile page.

I appreciate your advice, but for me, the proper directory is "C:\Users\MyFirstName\Documents\Wolfram Mathematica", even though Mathematica has a different opinion about what's proper. The directory I've named above is where I have version-control set up for Mathematica code.

I am grateful for your trying to help me get this working, but I really just want Mathematica to evaluate a file containing function-definitions, when I specifically request it. I don't want Mathematica to automatically evaluate these function-definitions. I only want them to be evaluated when I specifically ask Mathematica to evaluate them. And I'd hope I could keep this file in the directory I've set up for Mathematica files, because that's the location where my version-control is tracking files. That's the location where my bash scripts operate when I tell them to operate on Mathematica files. That's the location that my backup-software backs up when I run it.

There's no "just read this file and evaluate everything in it" command in all of Mathematica?

"Try Get["pathtofile"]"

Thank you, but that didn't work for me:

In[14]:= Get[
  "C:\Users\MyFirstName\Documents\Wolfram Mathematica\myLibrary.nb"];

During evaluation of In[14]:= Syntax::stresc: Unknown string escape \U.

During evaluation of In[14]:= Syntax::stresc: Unknown string escape \M.

During evaluation of In[14]:= Syntax::stresc: Unknown string escape \D.

During evaluation of In[14]:= Syntax::stresc: Unknown string escape \W.

During evaluation of In[14]:= Syntax::stresc: Unknown string escape \m.

In[12]:= Get[
  "C:\\Users\\MyFirstName\\Documents\\Wolfram \
Mathematica\\myLibrary.nb"];

In[13]:= ratioFromDb[4]

Out[13]= ratioFromDb[4]

"use the install menu item"

Now I've tried this too, and it too does not work.

Removing the double-quotes yields a new way to make this not work:

In[3]:= AppendTo[$Path, NotebookDirectory[]];

In[5]:= Needs[myLibrary2`]

During evaluation of In[5]:= Syntax::tsntxi: "Needs[myLibrary2`]" is incomplete; more input is needed.

In[4]:= ratioFromDb[4]

Out[4]= ratioFromDb[4]

So the Needs function doesn't have an option for setting Path, so I've gone back to trying the Get function. When I try

Once[Get["myLibrary.nb", Path -> NotebookDirectory[]]]

it prints out the entire contents of myLibrary.nb, and when it's done, the symbol ratioFromDb still is not defined. I could write a book on making this not work, but still having no idea how to perform this common task in Mathematica, so easy in numerous other languages.