Set minimum monthly EIR to 1% of the max monthly EIR

[acavelan]

This changes the minimum monthly EIR value to 1% of the maximum monthly EIR, which helps conserving the original length of the season better after smoothing (only applicable to when monthly EIR values are used).

When low values or even zeros are used in the seasonality, the Fourier smoothing struggles to find a good approximation and the resulting smoothed seasonality may not match the original input values.

Many users probably have this problem without realizing their smoothed input EIR in OpenMalaria doesn't actually match their initial monthly values.

To illustrate this, you can copy-paste the following monthly EIR values into this tool: https://swisstph.github.io/openmalaria/fourier The following values will crash the simulation when using the SimpleMPD model. You can see with the tool that the Fourier series does not match the input very well.

1.0
0.950484
0.850176
0.998646
0.592984
0.090076
0.002824
0.001974
0.019501
0.115986
0.440608
0.866085

However, adding 0.01 to the two smallest values solves the problem in most cases:

1.0
0.950484
0.850176
0.998646
0.592984
0.090076
0.012824
0.011974
0.019501
0.115986
0.440608
0.866085

This is an arbitrary solution but it seems to work well.

[nakul7]

As discussed on call