error bars - extra option

[Roberto]

Hi,

FEATURE REQUEST:
When opening the error bars dialog I see we only can choose from fixed OR percentage-wise error values. It's great to have at least a bit of error-bar support but I'm afraid it's only really useful for basic data (e.g. visual readings from an ordinary glass rod thermometer).

As far as I know in the very most (if not all) specifications of measuring devices (analogue as well as digital), the max. error of each measuring sample is expressed as a combination of fixed AND percentage, for example: 4 (least significant) digits + 0,5%. So at a reading of e.g. 1.965 the error might be 0.004 + 0.5% of 1.965 and rounded off to above to only 1 digit; in this case the real value might be 0.0138 higher or lower than the reading, officially thus 0.02 higher or lower than 1.965. So the error bars should be 0.04 long vertical bars in the plot.

So it would be praktical to have the combined fixed + percentage error as an input option in the error bars dialog in DPlot so users can easily create true error bars.

Best would be to extend this option a bit further: most measuring devices have not just one measuring range but more ranges, e.g. four to six ranges and each range can have a different error specification. To cover this it would be ideal to be able to input the error bars for all ranges in DPlot and that the DPlot- error bars dialog supports e.g. 8 ranges.
I was thinking of e.g. 8 input lines/ fields where we can enter per line:
min. Y-value / max. Y-value / fixed error for that range / percentage error in that range.

Hope this makes sense to the developers of DPlot and that the error bars feature of DPlot one day will be upgraded to a feature that covers real-world error expression

Cheers,
Roberto

[DPlotAdmin]

As far as I know in the very most (if not all) specifications of measuring devices (analogue as well as digital), the max. error of each measuring sample is expressed as a combination of fixed AND percentage, for example: 4 (least significant) digits + 0,5%. So at a reading of e.g. 1.965 the error might be 0.004 + 0.5% of 1.965 and rounded off to above to only 1 digit; in this case the real value might be 0.0138 higher or lower than the reading, officially thus 0.02 higher or lower than 1.965. So the error bars should be 0.04 long vertical bars in the plot.

Thanks for your input. I'll add this to my to-do list. In the meantime you can already do this with a bit of effort: Make a copy of your curve (Edit>Copy>Data values, Edit>Paste). Use Edit>Operate on Y with the copy and set Y=(for example) 0.004+0.005*Y. On the Error Bars dialog select "Different error values for every point", then select your copied and operated on curve for both the positive and negative values.

[Roberto]

Hi David,

A pleasure to hear that combined fixed & percentage error bars got on the to-do-list AND great to hear about the cool feature you described: the possibility to use other (error) curves for creating the error bars of a certain curve.
Very powerfull feature! Especially since the "Operate on Y"dialog also has an option to operate only on a specific X-range. This way it already is possible in DPlot to create error bars for data that is generated by measuring devices with different error specs in different measuring ranges! Just by using "Operate on Y" several times for the different measuring ranges

Thanks for letting me know about again an other very useful feature in DPlot!
Keep up the great work!
Roberto