Is it possible the force the streams in StreamPlot[] to extend the full range of the graphic given specific points of my choosing? For example, notice the streams for the following code are short. I would like to streams to extend through the entire graphic.
StreamPlot[{1, -2 y}, {x, -4, 4}, {y, -4, 4},
StreamPoints -> {{{1, 0}, {1, 1}}}]
Note, that the bottom stream should be a horizontal line all the way across the graphic through {1,0}. Any ideas? I've tried different settings for the StreamScale and StreamPoints options, but can't seem to lengthen the streams.

StreamPlot[{1, -2 y}, {x, -4, 4}, {y, -4, 4}, StreamPoints -> {30}]StreamPlot[{1, -2 y}, {x, -4, 4}, {y, -4, 4}, StreamPoints -> {5}]StreamPlot[{1, -2 y}, {x, -4, 4}, {y, -4, 4}, StreamPoints -> {{{{1, 0}}, 1}}]SteadmPlotcan only draw the local line, to draw the global line why not directly useNDSolve? – cvgmt Aug 19 '22 at 03:49