How can we control print and export margins?

Questions
1

I have been doing some work with the Control Theory stuff, and I would like to be able to print the graphics. For example, BodePlot. I can get plots, but I have not found a way to control the margins. FrameMargins does not seem to be an option in BodePlot, Show, GraphicsColumn, . .

I can get plots like the one attached, but the bottom margin is too small for use.

Any idea on how to go about this?

–David

2

I have come up with one method.

tfm = TransferFunctionModel[{{1/(s + 100)/(s + 10000)}}, s]

{mag, phase} = 
 BodePlot[tfm, PlotLabel -> {"Mag", "Phase"}, 
  ImageMargins -> {{{5, 5}, {5, 5}}, {{10, 10}, {10, 10}}}, 
  PlotLayout -> "List"]

bplt2 = GraphicsColumn[{mag, phase}, 
  ImageMargins -> {{20, 20}, {20, 10}}, 
  PlotLabel -> Style["Bode Plot", 20], ImageSize -> {8.5, 11} 72]

Export["bp10.pdf", 
 Rasterize[bplt2, ImageResolution -> 100, ImageSize -> {8.5, 11} 72],ImageResolution->100]

Here BodePlot provides separate mag and phase graphics. They are combined with GraphicsColumn into a desirable image, and then exported as a rasterized PDF. The PDF appears to be at 300dpi rather than the 100 specified.