node and npm....

I am clearly messing about with things I don't understand.
Usually, if I am using the dialog box, this is true but hey, I don't seem to have any choice if I want to make a good quality d3 map.

I found the following Introduction to npm  - so npm is a node programme manager.
It helps to install various node programmes.

In includes a warning about using sudo - the super user work around all the time.
Helpfully, it gives a solution too.

$ sudo chown -R $USER /usr/local

Ok, so it seems that using npm requires Xcode and I am pretty sure I don't have that installed.
Basically that's because some C+ compiling is required.
Answer here: http://stackoverflow.com/questions/22996677/why-is-npm-install-failing-because-of-xcode

Going to install Xcode 3.2
I'm working with earlier versions of things but hopefully it will work.

So, it does seem as if these have now worked.

I have installed Xcode 3.2 into a Developer folder in my local user area.

I have installed Contextify
$ npm install contextify

I have installed topojson
$ npm install -g topojson

$npm ls

gives this:

/Users/paulbrennan
└─┬ contextify@0.1.8
  ├── bindings@1.2.0
  └── nan@1.0.0