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To change the name of the model, type a name in the Properties window or change the name in the Project Explorer by clicking on the map.
The user interface will then look like the picture below:
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Be aware of the fact that if the values of the input map are outside the range of the broken linear function the result map will get no data. Add a large number if you want to model all values above (or below) a certain value to get the same value. In the example above: values from 0 to 3 and 12 to 15 will be reclassified as 0. Gridcells with a value above 15 will get nodata. If you want to avoid this, you should enter for example 10000 (or the known maximum value in the map) instead of 15.