Plotting results of 'Do' loop in contour graph

Question

I want to plot the results of a 'do' loop as a contour graph:

z = Reap[
  Do[
   Do[
    Sow[
     NIntegrate[Sin[a + b*x], {x, -10, 10}]
     ],
    {b, 0, 6, 0.5}
    ],
   {a, 0, 5, 0.5}
   ]
  ]

I get a list of values, but I'm not sure of the best way to rearrange everything to be able to plot a b vs a contour of z.

$\begingroup$ Would Table and ListContourPlot be any help? $\endgroup$
– Michael E2
Commented Mar 11, 2016 at 11:55 — Michael E2, Commented Mar 11, 2016 at 11:55
$\begingroup$ Related: (97293), (104318) $\endgroup$
– Michael E2
Commented Mar 11, 2016 at 12:18 — Michael E2, Commented Mar 11, 2016 at 12:18

David G. Stork · Accepted Answer · 2016-03-11 11:02:10Z

2

Why numerically integrate when you can precisely integrate?

ArrayPlot@(z=Table[
  Integrate[Sin[a + b x], {x, -10, 10}], 
  {b, 0, 6, 0.5}, 
  {a, 0, 5, 0.5}])

or

ListPlot[z, 
Joined -> True,
PlotRange -> All]

answered Mar 11, 2016 at 10:59

David G. Stork

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1

$\begingroup$ Yes, but I've just posted a MWE - I'm working on an integral that may not have an analytical solution. $\endgroup$
– Medulla Oblongata
Commented Mar 11, 2016 at 11:01
$\begingroup$ What is the integral you seek? By the way, you should almost never use Do in Mathematica... there are almost always superior ways to iterate, most notably Table. $\endgroup$
– David G. Stork
Commented Mar 11, 2016 at 11:03
$\begingroup$ Since you're interested, math.stackexchange.com/questions/1692773/… and I want to vary the 1 and 4, like a and b in this example. $\endgroup$
– Medulla Oblongata
Commented Mar 11, 2016 at 11:03

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