I forked data from the New York times, and graphed it,NY Times Covid19 database I formatted the data, and baselined the timeline to January 1, 2020. This is what the Florida dataset looks like when input to Maxima: (%i37) Florida; (%o37) [[2020-03-01, 2], [2020-03-02, 2], [2020-03-03, 3], [2020-03-04, 3], [2020-03-05, […]
Maxima
28 posts
In my post of Doubling Numbers – part 3 I predicted one million cases worldwide on March 28, 2020 — today. Well, I was wrong — there are 660,000 confirmed cases and 30K dead. That prediction was made on March 7, twenty one days ago when there were 21K cases. […]
I downloaded the data from the New York Times for confirmed cases covid19 state data from March 1 thru March 26, 2020. Then I plotted this in Maxima. (%i14) plot2d([discrete,NYlog],[title,"NY confirmed cases"], [xlabel,"March 2020 date"],[ylabel,"log souls"], [png_file,"nylog.png"]) (%o14) [/home/nicks/maxout.gnuplot, /home/nicks/nylog.png] (%o14) loveny.mac From eyeballing the graph, one can see that […]
The logistic equation is another model at which the finite population size starts limiting the process. As the number of cases approaches the population size, the rate slows. (%i8) diff(f(x),x)=gamma*f(x)*(G-f(x)); d (%o8) -- (f(x)) = (G - f(x)) f(x) gamma dx Here G is the total population size. As the […]
After a month of indecision, action has come. By restricting peoples’ movement and association, transmission of the virus can be delayed, or stopped. Makes sense in theory — the rapid growth of cases will peak and then subside. That’s the idea. But what does that mean practically? From a numerical […]
In my post on February 10 I predicted that there would be a million cases of coronavirus by March 1. Today, March 6, I am looking at the number of cases outside China reported as 2400 on February 24 and 1200 on February 20. One can use these values to […]
In my post on February 10 I predicted that there would be a million cases of coronavirus by March 1. It was a simplistic back-of-the-envelope calculation. On the same day, Donald Trump made the prediction, “Now, the virus that we’re talking about having to do — you know, a lot […]
a[0]:0; recaman:set(0); recaman_next(n):=block([x:a[n-1]-n], if (x > 0) and not elementp(x, recaman) then ( a[n]:x, recaman:adjoin(x, recaman)) else ( a[n]:a[n-1]+n, recaman:adjoin(a[n], recaman))); for i:1 thru 30 do (recaman_next(i), print(i,"=",a[i])); 1 = 1 2 = 3 3 = 6 4 = 2 5 = 7 6 = 13 7 = 20 8 […]
A very simple number sequence is n(0)=2, n(1)=23, n(2)=235, n(3)=2357, n(4)=235711, n(5)=23571113 where n(i+1) is the i+1 prime concatenated with n(i). So n(1) = concat(2, n(0)) = 23. This is called by many as the Smarandache sequence. Maxima code for this is, smarandache(n):=block([p:0,l:""], for i:0 thru n step 1 do […]
This is an easy calculation, just integrate the gravitational force to get GMm/r where r is the radius of the earth about 6378 km (or 6378*10^3 meters), M is the mass of the earth 5.9736*10^24 kilograms, G is the gravitational constant 6.67*10^(-11), and let us assume that our weight is […]
I created a text file with “just4root” as the contents of the file to look at what the linux command ‘sha1sum’ digests the file — nicks@grant:~$ cat shatest just4root nicks@grant:~$ sha1sum shatest caa707808838ff4c8ac838d08d4e137878aea3ee shatest With maxima, we can again calculated the hash and verify that it checks ok. (%i5) load(stringproc); […]
There are twelve semitones in a music octave, when frequency doubles. Dividing this doubling into twelve equal parts, yields the twelfth root of two. An interesting Maxima problem is to compute its convergents; These values agree with wikipedia and provide some sort of explanation https://en.wikipedia.org/wiki/Twelfth_root_of_two (%i3) 2^(1/12),numer; (%o3) 1.059463094359295 (%i4) cf(%); […]