Plot the following differential equation over a larger time window?

Questions
, ,
1

I am using differential equations to determine the rate of formation of certain compounds in an enzymatic reaction. I am having an issue however, when graphing the rate of formation of one of the compounds over 1,800 seconds (tmax) where I get a very strange graph that has many “jumps”. However, this issue is resolved when I reduce the window of time to 30 seconds (tmax2). I believe that the program is having issues graphing the differential equation over the larger window of time. Is there any way I can resolve this or a better alternative to this?

Thank you very much,
Nik

Graphing Problem Mathematica.nb (121 KB)

2

Hi Nik,

The plot zoomed into the steady-state value. Just add the option PlotRange->All to the Plot function to see the full range.

Plot[ {Evaluate[Purp[t] /. Mechanism]}, {t, 0, tmax}, 
 PlotRange -> All, AxesLabel -> {time (seconds), conc (mM)}, 
 PlotStyle -> {Green},  PlotLegends -> {Purpurogallin}]

PlotProblem.png
PlotProblem.png481×182 2.2 KB

3

Hi,

try the option PlotRange->All, i.e.

Plot[ {Evaluate[Purp[t] /. Mechanism]}, {t, 0, tmax}, 
 AxesLabel -> {time (seconds), conc (mM)}, PlotStyle -> {Green},  
 PlotLegends -> {Purpurogallin}, PlotRange -> All]

Best wishes,
Marco

4

Sorry. Your reply only came up for me after I posted mine.

Cheers,

Marco