Don't load a population rates sheet during initialization.

[celiot-IDM]

This is the first small step towards integrating the new population rates format.

In this step we turn off the initial read of the PopValues sheet. This could have been done a while ago, because the population rates sheet for a given Scenario is defined in the Scenario record, and is loaded when the Scenario is actually run.

[MeWu-IDM]

@celiot-IDM this change looks safe to merge, could you point me to the code where the population rates are loaded so I can take a close look there? thanks

[celiot-IDM]

@celiot-IDM this change looks safe to merge, could you point me to the code where the population rates are loaded so I can take a close look there? thanks

The population change rates are loaded by the SaveBaseSettings() function, in ehep_exp_control.R.

Here are the operative lines:

` # Load Population change parameter data from the appropriate Excel sheet, as specified in the Scenarios sheet.

popValsSheet <- BVE$scenario$sheet_PopValues

if (!is.blank(popValsSheet)){
GPE$populationChangeParameters <- loadPopulationChangeParameters(popValsSheet)
} else {
GPE$populationChangeParameters <- loadPopulationChangeParameters()
}

if (!is.null(GPE$populationChangeParameters)) {
BVE$populationChangeParameters <- GPE$populationChangeParameters
}
`
(BTW This little dance where the sheet is loaded into the GPE environment (GPE = "global package environment") then copied into the BVE environment (BVE = "baseline values environment") is an artifact from when the input sheets were all loaded at startup into the GPE environment. The next phase of tidying will be to load the input sheet values directly into the BVE environment.)