# How can I stop Mathematica from evaluating simulation runs every time I evaluate the notebook

I'm new to Mathematica, and I'm using it as a tool to my studies, specially in graph theory. Now I have to simulate a random graph a number of times to make the statistical analysis of these simulation runs, but I got into one problem, which is the fact that whenever I open and evaluate the notebook, Mathematica evaluates the cell with the simulation runs, thus changing the graphs being analyzed. How can I make the cell be evaluated just once and store the graphs for future uses?

• there seems to have a problem in using this solution, the results aren't stored after the notebook is closed. Totay Ive oppened the file to continue the analysis, and the variables where I've stored the graphs' simulation runs were empty. For exemple:igplgsim = Table[IGStaticPowerLawGame[1032, 1441, 2.899)], 1000]; and basimm2 = Table[RandomGraph[BarabasiAlbertGraphDistribution[1032, 1]], 1000];. the list with the results of the simulation runs were stored in these variables and I've saved after that, yesterday they had a list of graphs for me to analyze, today they are empty. – nicholas80 Apr 26 '17 at 12:52