Use the green up arrow to upload your file (preferably a worksheet) and insert a link to it.

The behaviour you described used to be a problem, but I think it has improved considerably in recent releases.  You might be running into numerical problems, but I can't be sure without a look at the actual code.

It all looks fine to me (except that you really should define, e.g.,  r1 rather than r1(t)).  I think the Maple plots are correct. 

What do you think is wrong with them?

I had a look at the plots and while the straight sections of the graphs look odd, they do actually represent the functions as calculated. You can check this by using the menus to change the plot style to "Point". That will draw a symbol everywhere Maple has calculated a value for the graph. The points are dense enough that the graph is accurate (unless your function fluctuates very quickly). I'm unable to comment on the correctness of the functions.

David Clayworth Maplesoft GUI Developer

Ah, the problem is that it is Maple 11.  In Maple 12 there are many points plotted in this range.  Here is the plot in "point" style

and in "line" style

As Robert had observed, there was indeed a change to the log plotting commands in Maple 12 that resulted in better sampling.  I would still encourage you to upgrade to Maple 12 as there are a number of other plotting improvements (e.g. polar axes, dual-axis plots) that you may find useful. However, there is a workaround in Maple 11. You can use the 'sample' option with the plot command to specify a list of points at which you want the function sampled. If you want only those points sampled and no additional ones, then also add the adaptive=false option. These options are described on the plot/options help page.

Paulina Chin
Maplesoft

I'll try to explain the differences between Standard and Classic without getting overly technical. Users just interested in using the log plotting commands without knowing about the underlying structures can ignore this.

In Maple 11, we introduced the new 'axis' option to allow better control of the axes, but this is available only for the Standard interface. The 'axis' option has a 'mode' option that allows one to specify a log axis. The log axis is created by the GUI renderer based on the data sent to it from the math library routines.

We'd updated the log plotting commands to use the new way of creating a log axis. The problem with the sampling was simply an oversight that occurred when the code was being updated, and we corrected this in Maple 12.

Unfortunately, because Classic interface does not support the new 'axis' option, it still uses the older log plotting code. The results (apart from the sampling in Maple 11) are not ideal. The older log plotting code created the axis and its associated labels in the math library routines, which meant that the result had to be independent of the plotting device. This meant that a plot might have nice looking tickmarks and labels with one device but look awful with another. The heuristics used to create the labels were not particularly strong and improving them was difficult.. The current solution leads to much improved plots.

As Robert suggests, you can indeed use `plots/loglogplot` to get the older-style log plot in Standard with Maple 11. However, `plots/loglogplot` is an internal routine. We don't prevent users from calling internal routines but we do try to discourage it. We try very hard to maintain backward compatibility for all documented routines, but we can't guarantee that we'll never change the behaviour or calling sequence of an undocumented internal routine.

Paulina Chin
Maplesoft