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[REBOL] REBOL dynamic graph code problems and REBOL mindset

From: johnmacshea:gmai:l at: 21-Feb-2008 10:15

Hello REBOLers, I am a recent returner to REBOL, about 5 years ago I wrote some scripts but they were mainly simple message based, and now I can see some potential cool solutions in my company, if I can get over some initial stumbling blocks. I am trying to do some graphical manipulation, but I am having difficulty in doing some of the simplest things. Here is a simplified version of what I have and what I would like to do. I have a rebol script that shows a line graph based on a time series of data. When I manually set the data for each individual time series everything works fine, its only when I try to update the view and make things a little more dynamic do things start to go awry. I think I am being caught by a combination of type issues and functional language (as opposed to command/procedural based issues), and just some commands that I dont yet understand. So here is a snippet. data0: [100 110 105 120 ...] plot0: copy [pen green line] x: 10 foreach y data0 [append plot0 as-pair x y x:x + 1] graph_view: layout [the_box: box snow 1000x500 effect reduce ['draw plot0]] view graph_view This works fine - I may have left out a couple of things - but thats basically the graphing code. When I manually add a data1, plot1, data2, plot2 etc, it also works fine. However when I try to do something, which i would of thought is incredibly simple, things come unstuck. For example, I cant seem to put all the plots into a series, and then iterate over them later in the graph view. What i really want to do is add something like this (pseudo-ish code)to the graph_view: foreach current_curve in curves[ toggle_for_current_curve: "on" "off" [either value = true [add current curve to curve series if not there (then) show the_box] [remove current curve from the curve series if there (then) show the_box] I've spent about a day trying to get the simplest version of this scenario going without even the buttons above- which is just to push each (manually described) plot into a series, and then iterate over them to draw the different curves. I have pulled out the effect called it box_effect, and tried to do this before the layout code. I went through a whole bunch of iterators trying various ones, different ways of adding to series, and eventually through trial and error got a functioning box_effect, which however had the same curve multiple times, I think its something to do with dereferencing the draw and the plot functions. Here for example is me trying to create the box_effect. (having already created a plot0, plot1, and plot2 above this) box_effect: [] all_plots: reduce [plot0 plot1 plot2] plot_length: length? all_plots repeat index plot_length [a_plot: pick all_plots index append box_effect ['draw a_plot] ] This kind of works (I went through quite some iterations to get here, for each did not seem to always work, insert into a series did not seem to work, sometime pick series index_var, did not seem to work, sometimes the plot was 'none' etc etc) - now it gives me the same curve three times. This post is not just a query as to how i do such a simple thing, but more a question as to "how to 'get' REBOL", it just seems too hard to do something so simple, I feel like I am fighting the language, that my mindset is wrong, but I cant seem to figure out how to do it right. Any help would be much appreciated ! Best regards, John