University of Bremen

Manual


Tutorial Exercise 3.1: Get an Overview with Scaling

First you have to load a graph in uDraw(Graph) by using menu File/Open.... We suggest to use file "graph_example.udg" in the "samples/graphs" directory of the distribution again (refer to section 1). Afterwards, start the graph layout algorithm with menu Layout/Improve All.

Scaling is a feature to reduce the size of a probably large graph visualization for getting an overview. In a scaled graph, some details are dropped (e.g. the text of nodes is not drawn), but all the other interactions are still available, even in very small scales. So for example, you can use fine-tuning in a scaled drawing of a graph. One way to reduce the scale is by selecting menu View/Fit Scale to Window. Do this right now! A new (maximal) scale is calculated and set so the graph is completely visible in the base window. Of course, this modifies the scale only if the actual graph is larger than the base window. Shrink the window in this case to use the fit scale feature.

Now open the scale dialog by using menu View/Scale.... In this window you can set the scale to any rate between 1% and 100%. Simply move the slider to some arbitrary values and observe the effect on the visualization. Pressing button "Fit to Window" in the dialog is the same as selecting the menu you have used before. You cannot magnify the graph this way (i.e. there is no scale larger than 100%), but you can use a larger font for magnification as it is discussed in the previous tutorial section 2.

Before going to the next exercise, set the scale back to 100% (there are different ways to do so, for example by clicking on the "Large" label in the scale dialog) and afterwards finish the dialog by pressing the close push button.

End of Exercise 3.1. Go back to the Section 3 Overview.