Modify Previous Data Points

[davidw]

Is it possible to modify a data point which has already been calculated? Like this:

setValue[-20] = x;

I want to modify previously-calculated values based on the most current data.

[gspiker]

It sounds like what you want to do is modify already drawn data points. So if the question is, can I redraw those data points the answer is maybe, depending on how those points were put onto the chart.

The most common way to draw data onto a chart via EFS is via the return() function, where you place a value or value(s) into the return (eg: return(MyValue) or return new Array (12, MyValue, MyValue2).

I don't know of a way to redraw these lines within EFS. As a poor work around you could always display an alert whenever you want the user to refresh the study, but that is a total kludge.

Way early in the EFS development, I needed a way to draw on places on the chart other than the current bar, so Matt quickly put togther the drawLine() functions. This the other way to plot lines on a chart, and with the drawLine() functions. (There is also drawImage and drawShape and drawText that allow you to add data to a chart, and since it isn't clear what type of data you have I will add that everything I'm about to say about drawLine() applies to these also, except of course that it is text, image etc, rather than lines). This allows you to draw lines anyplace on the chart, and also (if you keep a list a the unique tags) allows you to remove lines from the chart. The downside to drawnLine() functions (other than it is more cumbersom to use than just return) is that the values of the drawn lines do not show up in the cursor window.

What it might be nice if eSignal implemented was a way for an efs formula to request that it be reinterated, with the same effect as if a user did a reload of the formula. This would allow you to do what you want, and be a nice addition to allow us to do other things as well. You might put in a request for this from eSignal.

[davidw]

Thanks for the reply. It sounds like it's not possible at this time.