tazatel

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9 years, 252 days

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These are questions asked by tazatel

I have a data point set:

relativní_tlak:=<0.063018,0.078419,0.119628,0.159668,0.199865>:

ads_mnozstvi:=<0.001467443666,0.001528693055,0.001659939952,0.001774105924,0.001883866808>:

I wanna make the least square fit with function in form of:

bet:=(x/(1-x))/((1/(a*b))+(((b-1)/(a*b))*x)):

also the command looks like:

with(Statistics):bet_nejmensi_ctverce:=NonlinearFit(bet,relativní_tlak,ads_mnozstvi,x,parameternames=[a,b],output=parametervector);

I found out the least square fit is not correct using the near-zero values in 'ads_mnozstvi' vector (the parameters have no physical sense).

The correct a,b values can be obtained when 'ads_mnozstvi' values are multiplied by 1000. The correct a,b values thus are:

[1.56257913677048,108.232791649022]

Why Maple cannot make correct fit with near-zero values?

I have a dataset:

NMP:=<0.530,0.555,0.572,0.592>:
ETOH:=<0.136,0.153,0.163,0.170>:

For these four data points [NMP,ETOH] I want to find the least square function in form of:

ln(ETOH/(1-ETOH-NMP))=a*ln(NMP/(1-ETOH-NMP))+b

also I need to find appropriate a,b constant values.

This function is implicite so I cannot use with(Statistics):NonlinearFit.

Can you help me how to determine a,b constants?

I have some vector field defined on real coordinate space of 3 dimensions (R3). For example:

I want to plot this vector field in 3D (with Cartesian coordinates), but only in one z contour (for example z=0).

Can somebody help me what is the right command to do this?

I have data matrix in text file.

I opened it with Maple and replaced decimal commas to decimal points + replaced column separator to semicolon.

Then I set 'Convert to plain text'.

After these modifications, I would like to export that Maple worksheet back to .txt  file with content exactly as shown on the display.

But if I export the worksheet as Maple text, extra pound signs are added to the beginning of each row. In this case I cannot import data to matrix datatype=float.

If I export the worksheet as Plain text, all the rows are destroyed and I cannot import data into matrix as well.

How can I export worksheet content, exactly as shown on display, into text file?

I want to solve one equation with one variable and the variable is also in definite integral delimiter. When trying fsolve, I get the error:

"Error, (in fsolve) Can't handle expressions with typed procedures"

code

Here is worksheet.mw

How can I obtain solution with method other from simple manual testing Te values?

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