# Movie monitor magnitude

#1

Hello,

I have a question regarding the colour scale of movie monitors.
I have a movie monitor recording the electric field intensity. The scale is equal to 1.0 (the default). After running the simulation I see that the variable “Monitor name_maxI” = 180.224.
As I understand, ‘scale’ is a dimensionless variable, but is it possible to determine the value of the electric field of the ‘maximum colour’? (I am interested in a screen shot at certain times in the simulation.)
To be clear, I would like to know the value of the electric field of the ‘maximum colour’ when:

1. The scale is 1.0.
2( The scale is changed to 180.224.

Also, what type of scale is used? Linear or log?

Thank you

#2

Dear @ie5003_allison

The movie monitor uses jet colormap in which electric field intensity are scaled from 0-1 and colors from dark blue to dark red, respectively. It looks like this is the only available colormap option for movie monitor. If you want to extract raw data and do post processing to plot them in other colormaps, please see my notes at the end of this post.

When the scale factor is 1.0 (default value), any field value that is above 1 will be represented by dark red. Thus, when the maxI value is other than 1 (in your case it is 180.224), you will need to set scale factor to maxI value so that maximum value is normalized (i.e. =1) and you are using full potential of jet colormap. After normalization, you can add a color bar where its maximum is maxI as is shown below:

Please note that scale factor does not change the intensity values, and it is for normalizing the colors in the movie monitor to be properly represented by jet colormap.

If you want to do more analysis or use other colormaps, you can use a 2D time monitor to capture the electric field components in time. Than you can use this data to calculate intensity in time and then plot it.

I think cw movie might be interesting as well to take a look at it. In this case electric field data are captured by DFT monitor (in frequency domain) which then can be inverse Fourier transformed to be represented in time domain. You can then use this time domain field data to visualize the intensity.