To add a Value Column subnode, right-click the Least-Squares Objective node. Use a Value Column to identify a column in the experimental data file as containing measurement values. Enter a corresponding Expression, which must be available for evaluation on the geometric entities selected in the node. Enter a corresponding Column contribution weight, which must be strictly positive and be available for evaluation in the global scope in the current model.

Optionally, a Variable name can be specified to enable access to the data from the file for postprocessing. Note that the variable will be defined in only the data points (parameter value, time, and coordinates) from the file. In postprocessing, it is necessary to evaluate in the data points to ensure an adequate visualization. One option is to use a Point Evaluation or Point Graph feature with a Cut Point 1D (2D/3D) dataset. The Cut Point dataset is available as a subnode under the Datasets node. In the Point Data section in the Settings window for the Cut Point 1D (2D/3D) dataset, you can use the From file option from the Entry method list. Other options for postprocessing the experimental data are interpolation functions and tables (use a new Table node with data imported from the least-squares objective file in that case). A Unit can also be specified if desired, using the syntax for a valid unit definition in the COMSOL Multiphysics software. The difference between the Expression and the value from the file is squared and multiplied with the Column contribution weight and a factor 0.5 to give the contribution to the total objective for each measured value.