few more details for 2D FC

docs/part3/commonstatsmethods.md

@@ -1048,7 +1048,7 @@ text2workspace.py -m 125 -P HiggsAnalysis.CombinedLimit.PhysicsModel:floatingXSH
 ```
 
 First, we use `combineTool.py` to create jobs for each point in our parameter scan. We want to impose the boundaries that $r_{ggH}>0$, $r_{qqH}>0$.
-In the example below, we will run in interactive mode so this can take a little while. You can instead run in batch or grid submission mode to submit jobs for each point. We configure the tool by specifying the grid of points in `grid.json` as below. Here we want 5000 toys for each point, and we choose a grid of $r_{ggH}\in [0,4]$ in steps of 0.2, and $r_{qqH}\in[0,10]$ in steps of 0.5.
+In the example below, we will run in interactive mode so this can take a little while. You can instead run using a batch cluster (eg `condor`) or the grid (`grid`) to submit sepaerate jobs for each point / set of points. We configure the tool by specifying the grid of points in `poi_grid_configuration.json` as below. Here we want 5000 toys for each point, and we choose a grid of $r_{ggH}\in [0,4]$ in steps of 0.2, and $r_{qqH}\in[0,10]$ in steps of 0.5.
 
 ```
 {
@@ -1071,16 +1071,17 @@ In the example below, we will run in interactive mode so this can take a little
  }
 ```
 
-The command will look like
+The command will look like,
 
 ```sh
-combineTool.py -M HybridNewGrid  ./grid.json -d toy-hgg-125.root --task-name fc2d --job-mode 'interactive' --cycles 1
+combineTool.py -M HybridNewGrid  ./poi_grid_configuration.json -d toy-hgg-125.root --task-name fc2d --job-mode 'interactive' --cycles 1
 ```
 
-Once this is done, we extract the values of $p_{\vec{\mu}}$ for each point in our parameter space using
+As mentioned, this will take a while to run so you should consider going to make a cup of coffee at this point and reading through the [HybridNewGrid documentation](http://cms-analysis.github.io/CombineHarvester/md_docs__hybrid_new_grid.html) to learn more about this tool.
+Once this is done, we extract the values of $p_{\vec{\mu}}$ for each point in our parameter space using the same command, but this time setting `--cycles 0` and adding the option `--output`,
 
 ```sh
-combineTool.py -M HybridNewGrid  ./grid.json -d toy-hgg-125.root --task-name fc2d --job-mode 'interactive' --cycles 0 --output
+combineTool.py -M HybridNewGrid  ./poi_grid_configuration.json -d toy-hgg-125.root --task-name fc2d --job-mode 'interactive' --cycles 0 --output
 ```
 
 which will produce a file `FeldmanCousins.root` that contains a `TGraph2D` which stores the calculated value of $p_{\vec{\mu}}$ for each point in the grid. The script below can be used to draw these values and extract the contour corresponding to 68% CL ($\alpha=0.32$).