MaplePrimes - Maple 2022 Posts and Questions

How to get a date from a Julian Day Number

Jno — Sat, 04 Apr 2026 16:02:41 Z

Hi,

Is there a way to get a date from a Julian Day Number in Maple? I can easily calculate a Julian Day Number in Maple, but sometimes I need to go in the other direction. I have searched for a solution. Google AI has suggested a couple solutions, but the Maple commands it gives don't seem to exist (certainly not in Maple 2022.2).

Thanks,

John

Delta symbol in name

Tycho Brahe — Thu, 19 Mar 2026 01:39:14 Z

I am trying to use the symbol Delta in front of a symbol to denote a change in the variable in Maple 2022.For exmaple Q':=Q+Delta_Q; But I can't figure out how to denote it: Delta_Q does not seem to work as it displays a literal "Delta_Q".

Trouble browsing large vector or matrix

Jno — Tue, 17 Mar 2026 00:06:10 Z

Hi,

I was running Maple 2022.2 on Windows 11 and now I am using Linux Mint. I ran into something today that doesn't work as expected on LM. I thought it did on Windows, but now I am not so sure.

At any rate, I am unable to browse large vectors or matrices with more than 10001 rows. I looked for a setting that lets me change it, but I can't find one. The data is there--I can plot it and export it, but I can't browse it.

Any thoughts? Thanks.

Cheers,

Jno.

Display region boundary in plot?

Andiguys — Mon, 09 Mar 2026 07:35:12 Z

I have generated the regional plot, but the boundaries between the regions are not clearly marked. How can I highlight the boundaries using a black line or a black dashed line, similar to the example image? What syntax should I use? I have attached my generated image file.

Regional_new.mw

Legend error in multi-curve plot

Andiguys — Wed, 04 Mar 2026 06:21:44 Z

I would like to plot multiple curves in a single graph with proper legends for different values of θ, similar to the sample figure. However, I am encountering an error while generating the legend. What modifications should I make to correct this? Additionally, how can I display labels such as θ=0.4, θ=0.5 etc., directly inside the plot as shown in the sample?

Graph_legend_error.mw

Mistake in solving?

Andiguys — Mon, 02 Mar 2026 10:39:47 Z

When I solve for Pr and q simultaneously using Maple, I obtain a solution that differs from my manual derivation. I suspect there may be an issue with the solve function or the way it is specified. Could anyone please suggest how this can be corrected?
Manually solving q* = (Cv-Cd+Ce*tau-Ci)/(4Cr-t) which is different from maple results.

Sheet:Question_1.mw