A: This error message is caused by having non-calculation variables defined in the input columns in a calculation file. Take for example, a diagram.xml file for a plot with four elements – Ti, Zr, Nb and Y. The axis are derived from calculation based on these input variables. Axis X is Ti/Zr and axis Y is Nb/Y. These ratios are defined in the <GeochemFunction> row in the diagram. xml file.
This diagram will work fine when the user has assay data for the four elements (Ti, Zr, Nb and Y). But say for example, if a new batch of drillhole data came in and it does not have assay data for Nb, the diagram obviously won’t run. Then the first thing that the user would do is to remove Nb from the ratio calculation, and change the ratio to something arbritary (as an example, 50/Y instead of Nb/Y). But when the user does this, Nb is still referenced to in the diagram xml file as an input variable, and an error message will show up saying “Unable to open diagram. Nb_ppm – missing or non-numeric”.
To keep this error message from appearing, it is important to remove non-calculation variables from the list of input columns.