MATLAB: Ezplot fails to plot

function equation differential system ezplot plot complicated

I am currently working on a very complicated plot obtained from solving system of 25 differential equations.
The resulting plot should look like an exponential decay. I am 100% sure that the plot range is in the right place.
However, only very short range is plotted in ezplot. It suddenly cuts off at a certain 't' value.
It looks like this:
(exp(44076718174000119488089/4398046511104000000000000000000000000 – (44076718174000119488089*t)/4398046511104)*heaviside(t – 1/1000000000000000000000000)*(4835908122725230768047511886758352784202215283460756517106483200*exp((1377397326799331872275*t)/137438953472 – 55095893071973274891/5497558138880000000000000000000000) – 21822804986935542488305495815699038208*exp((44076450240050567389817*t)/4398046511104 – 44076450240050567389817/4398046511104000000000000000000000000) + 2030859531944623809729207891340025*exp((44076052898326019322713*t)/4398046511104 – 44076052898326019322713/4398046511104000000000000000000000000) – 18085634090625306713632872272494592*exp((44076052898326019322841*t)/4398046511104 – 44076052898326019322841/4398046511104000000000000000000000000) + 899841683603599959456792245698560*exp((44076052898326019323737*t)/4398046511104 – 44076052898326019323737/4398046511104000000000000000000000000) + 16859145488020262757774129136402432*exp((44076444021324750850777*t)/4398046511104 – 44076444021324750850777/4398046511104000000000000000000000000) – 814216110518877199209330571739136*exp((44076499305661593367385*t)/4398046511104 – 8815299861132318673477/879609302220800000000000000000000000) – 59996389385486985376868742957341184*exp((44075613477633556029145*t)/4398046511104 – 8815122695526711205829/879609302220800000000000000000000000) – 5585274059419732529680339483843837206736628160716523821019955200*exp((44076448937248382280633*t)/4398046511104 – 44076448937248382280633/4398046511104000000000000000000000000) + 2237444409888768455238992971956224*exp((44075613477633556027225*t)/4398046511104 – 1763024539105342241089/175921860444160000000000000000000000) + 723346804237244208838146923150757888*exp((44076450624009214494457*t)/4398046511104 – 44076450624009214494457/4398046511104000000000000000000000000) + 2339736958591406137822707047806795776*exp((44076450624009214494649*t)/4398046511104 – 44076450624009214494649/4398046511104000000000000000000000000) – 268336364735555131827998618577920000*exp((44076450624009214494809*t)/4398046511104 – 44076450624009214494809/4398046511104000000000000000000000000) + 499178652185299258833824396018974720*exp((44076450624009214494969*t)/4398046511104 – 44076450624009214494969/4398046511104000000000000000000000000) – 1308598970657934425299226132398012991771653075086868480*exp((8292132738039488089*t)/4398046511104 – 8292132738039488089/4398046511104000000000000000000000000) + 749365938003100155014933091149451847841073721731585070375895040*exp((44074735369117811027289*t)/4398046511104 – 44074735369117811027289/4398046511104000000000000000000000000)))/52656145834278593348959013841835216159447547700274555627155488768
I know this is horrendous work for MATLAB (and my PC), but it is very important that I can plot this because it is a very important data for writing a paper.
IS there any way I can forcefully make MATLAB plot all the way through (at least t = 0 to 0.005)?

Best Answer

Your sub-expressions that are similar to
exp((44076444021324750850777*t)/4398046511104 - 44076444021324750850777/4398046511104000000000000000000000000)
are overflowing when evaluated numerically with t more than about 0.0005. That is leaving the values undefined.
The function is clearly created symbolically. You will need to keep it symbolic and evaluate it symbolically at an array of specific t, then convert the symbolic result to numeric form to print. When you do that the symbolic exponents can cancel enough to give you a usable result.
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