Coffeescript: Conditional variable in for loop not declared correctly

Question

I am using coffeescript to render a plot graph. I had previously posted a question about setting up the conditionals; which I believe is now solved. However, the variable curr_visibility, used for one of the conditionals, is causing an issue I think, because it is not defined correctly. The graph plot essentially works like this; a 0 (not visible) or 1 (visible) is assigned to each point on the graph (the points are used to draw a line that is essentially a terrain profile coming from a map using a DEM image). I am attaching a screenshot which illustrates my bug (LV = lastVisibilty and CV = curr_visibility). The variable curr_visibility is inside a for loop. I need to make sure that it is updated after each iteration, but I am just not sure it is set up properly to work inside my fillColor: if conditional statement. the code starts with two empty sets- line = [] and datasets = [] Plot graph showing the bug. The area between LV and CV should be red for No visibility

prev_visibility = data[0].visibility
        for elem, index in data
            curr_visibility = elem.visibility

            point = [
                index
                elem.geometry[2]
            ]

            line.push point
            unless prev_visibility is curr_visibility
                datasets.push line
                line = [point]
                prev_visibility = curr_visibility

        datasets.push line

        line = []
        lastVisibility = data[0].visibility

        newfillColor = if lastVisibilty == 0 && curr_visibility == 0
                "#C90E30"
            else if lastVisibilty == 0 && curr_visibility == 1
                "#439C32"
            else if lastVisibilty == 1 && curr_visibility == 0
                "#C90E30"
            else
                "#439C32"

        for set in datasets
            line.push 
                data: set,
                lines:
                    show: true
                    fill: true
                    opacity: 0.7
                    fillColor: newfillColor

            lastVisibility = 1 - lastVisibility

gwydion93 · Accepted Answer · 2016-05-10 17:46:24Z

1

OK, with the help of a coworker, I was able to resolve this issue. First, in the code above, every instance of the variable prev_visibility was removed. It was determined not to be necessary. Second, we determined that index method needed to be utilized to relate to a new variable, next_visibility, that would compare the current visibility value of a point to that of the next for every iteration (I hope I'm explaining this correctly). To do this, we added the following:

line.push point
if (index + 1) < data.length
    next_visibility = data[index + 1].visibility
else
    next_visibility = curr_visibility

unless next_visibility is curr_visibility
    datasets.push line
    line = [point]

Finally, all of the newFillColor stuff was removed and I reverted back to fillColor: if lastVisibility is 0 then "#C90E30" else "439C32"

answered May 10, 2016 at 17:46

gwydion93

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