Mathematica: dynamic number of menus - dynamic

Question

I am trying to make a dynamic number of drop-down menus in a plot, to plot a various number of curves.
I have previously requested help to plot this data, and it worked well.
First thing
Needs["PlotLegends`"]
Here is a example of data (not actual numbers, as they are waaay too long).
data={{year, H, He, Li, C, O, Si, S},
{0, .5, .1, .01, 0.01, 0.01, 0.001, 0.001},
{100, .45, .1, .01, 0.01, 0.01, 0.001, 0.001},
{200, .40, .1, .01, 0.01, 0.01, 0.001, 0.001},
{300, .35, .1, .01, 0.01, 0.01, 0.001, 0.001}}
The compounds variable is the number of compounds+1
compounds=8
For now, my code is this one
Manipulate[
ListLogLogPlot[
{data[[All, {1, i}]],
data[[All, {1, j}]],
data[[All, {1, k}]]},
PlotLegend -> {data[[1, i]],
data[[1, j]],
data[[1, k]]}
],
{{i, 2, "Compound 1"},Thread[Range[2, compounds] -> Drop[data[[1]], 1]]},
{{j, 3, "Compound 2"},Thread[Range[2, compounds] -> Drop[data[[1]], 1]]},
{{k, 4, "Compound 2"},Thread[Range[2, compounds] -> Drop[data[[1]], 1]]},
ContinuousAction -> False
]
As you can see, I can easily add a compound by duplicating each of the 3 lines (data, legend and menu descriptor), but it's lame and inefficient. Plotting a set takes about 20 seconds, so it's about 1 minute here (and I use a pretty efficient cluster).
Is there a solution to add a little menu or field where I can add the number of compounds to plot, so the right number of menus will display? I don't need more than 7 plots, but efficiency...
The numbers 2, 4, 16 are the default values to plot. I can make a list with the default values (2, 14, 16, and some others I may pick), or they could all be set to 2.
Thanks

Answer 1

You could do something like this
Manipulate[
ListLogLogPlot[data[[All, {1, #}]] & /# i],
{{n, 3, "# compounds"}, Range[7],
Dynamic[If[Length[i] != n, i = PadRight[{2, 4, 16}, n, 2]];
PopupMenu[#, Range[7]]] &},
{{i, {2, 4, 16}}, ControlType -> None},
Dynamic[Column[
Labeled[PopupMenu[Dynamic[i[[#]]],
Thread[Range[2, compounds] -> Drop[data[[1]], 1]]],
Row[{"Compound ", #}], Left] & /# Range[n]]
]
]
Without PlotLegend, this runs quite fast for a random data set of about 1000x1000 elements. If I include the PlotLegend option in ListLogLogPlot, it slows down quite a lot so that might be the reason why your code was so slow.

Answer 2

I thought I'd add a DM version. If you're like me you may find that easier than using manipulate. It is essentially a DM version of Heike's answer.
DynamicModule[{data,compounds,n=1,c={2},labels},
data=yourData;
compounds=Length[data[[1]]];
labels=Rule###Transpose[{Range[7],data[[1,2;;]]}];
Column[{
Dynamic[
Grid[
Join[
{{"no. of compounds",PopupMenu[Dynamic[n],Range[7]]}},
Table[
With[{i=i},
c=PadRight[c,n,2];
{"compound"<>ToString[i], PopupMenu[Dynamic[c[[i]]],labels]}
],
{i,n}
]
],
Alignment->{{Right,Left},Center}
],
TrackedSymbols:>{n}
],
Dynamic#ListLogLogPlot[data[[All,{1,#}]]&/#c]
}]
]
I've used Grid because it allows you to easily keep all the controllers and their labels aligned. PadRight[c,n,2] allows you to keep current settings if you change the value of n. I'd avoid plot legends and always make your own.

Answer 3

How about something like:
Manipulate[
Manipulate[ ListLogLogPlot[Table[Subscript[x, n], {n, 1, numCompounds}]],
Evaluate#Apply[Sequence,Table[{{Subscript[x, n], n + 1, "Compound " <> ToString#n},
Thread[Range[2, compounds] -> Drop[data[[1]], 1]]}, {n, 1,
numCompounds}]], ContinuousAction -> False],
{{numCompounds, 3}, 1, compounds - 1, 1}]