CODEWITHSUNDEEP
plotpointmaxima
Joseph Watkins
Joseph Watkins

Reputation: 21

How can i plot a single point using maxima/wxmaxima?

Im writing a basic script to find the min distance between f(x):=log(x)-x and the origin. I would like to be able to plot the point closest to the origin over the top of a plot of f(x), but i can not figure out how to plot a single point.

Here is what i have written. Any ideas?

f(x):=log(x)-x;
d(x):=sqrt(x^2+f(x)^2)$
find_root(diff(d(x),x),x,0.01,5)$
a:%;
f(a);
print("min distance from f(x) to (0,0)")$
d(a);
print("passes second derivative test if next value greater than zero")$
g(x):=''(diff(d(x),x,2))$
g(a);

wxplot2d([f(x)], [x,.01,5], [y,-6,0])$

Upvotes: 2

Views: 3355

Answers (1)

Fred Senese
Fred Senese

Reputation: 670

Use the discrete option as a second curve, and then use points in the style option.

Replacing your last line with

wxplot2d([f(x), [discrete, [a], [f(a)]]], [x,.01,5], [y,-6,0], 
    [style, lines, points],
    [legend, "log(x)-x", "closest point to origin"], 
    [point_type, circle], 
    [gnuplot_preamble, "set key bottom"])$

gives you this:

enter image description here

Upvotes: 2

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