Archive for November, 2010

Creating a heatmap with Photoshop (for NodeXL)

Hi everybody,

i spent the past hours searching for a nice way to create a heatmap for NodeXL. The aim was to provide something like this for any given NodeXL network. By the way, this technique presented here is not limited to Node XL networks. You can create a heatmap for almost everything using Photoshop (just skip step 1). If you don’t want to go through the whole process, you can download the PSD-file used here.

Edit: At the moment, all the heatmap-ish look has to be applied manually. If you have a good idea how to copy-paste a network and get to the same results, please comment.

1st step: Exporting your networks

In NodeXL, export your image as png. Preferably, you take a black background with white node and edge color. By then, you should have something like this:

2nd step: Preparing Photoshop

Open the image in Photoshop, and create 2 more layers. One background-layer and one to paint on later. You can fill the background with any violet-blue color. In this case it’s RGB 77/4/120.

3rd step:  Applying layer style effects on layer 2

In step 4 i want to paint the heatmap on layer 2. Therefore some layer style effects are needed. Select layer 2, click on the layer-style button (“fx”) and activate “Outer glow”. Set

  • “Blend mode” to “negative multiply”
  • opacity to 90%
  • spread to 10%
  • size to 20 px
  • range to 100%
  • and the rest to 0.

Next, we need that rainbow gradient. Just set the colors like shown beneath. It’s:

  • white, red (255/0/0), yellow (255/253/0), green (30/255/0) and blue (10/0/178)
  • important: set the upper stops to the following opacity values: black=100%, darkgrey= 80%, light grey = 55%)

4th step: Adjusting the brush

Select a brush and do some settings. In this case, i activated shape dynamics and smoothing. Set the opacity of the brush to 1% (as color, choose the background color), and to a size which seems appropriate for your needs (here: 5pxls). Go back to your layer 2 and now paint over your network. You should get something like this:

Or without the network-layer 1:


The method presented here shows how to manually create a heatmap of any given NodeXL network with Photoshop. Since this is not an automated process, you can actually create a heatmap out of everything (if you have enough time and creativity). For example an “infrared-image” of a human person:

If you have any suggestions how to simplify this process to make it more scaleable, please write a comment! Have fun.


#S21 auf Twitter: Ein Visualisierungsversuch mit NodeXL

Was gibt es gemütlicheres am Sonntagmittag als eine Tasse Kaffee, im Internet surfen und ein kontroverses Städtebauprojekt auf Twitter mit NodeXL zu analysieren? Eben. Die untenstehenden Netzwerkansichten verdeutlichen wie sich #S21 in den letzten Tagen über Twitter verbreitet hat (in 6 Stunden Schritten). Ein Kästchen stellt dabei ein Twitter-User dar, die Größe des Kästchens sein Indegree-Wert, d.h. wieviele andere Twitter-User ihn erwähnen. Die vier roten User sind diejenigen, die in der Diskussion am zentralsten sind (=den höchsten Indegree-Wert aufweisen).

13.11.2010, 12h

13.11.2010, 18h

14.11.2010, 00:00h

14.11.2010, 12:00h

Man sieht sehr schön wie die einzelnen User sich über die Zeit hinweg vernetzen. Was sich auch erahnen lässt, ist, dass die zentralen Twitterer (rot) sich gegenseitig kaum erwähnen. Hier kommen dann ganz andere Nutzer ins Spiel, die eine Brückenfunktion (blau, groß) einnehmen:

So, das wars fürs Erste. Brauch erst mal nen frischen Kaffee. Für Anregungen und Analysevorschläge bin ich jederzeit offen 🙂

Sorry, tumblr

just moved from tumblr to wordpress. maybe i’m old fashioned but i just like to have a comment feature and some easy stats tools. farewell, tumblr!