a simple calculation by each row

I have 11 variables with each 24 rows. Therefore the data has 24x11 matrix.

I need to find out a vector x that is unknown. It is calculated each row by each row.

I believe this is really a simple task, but it gives me an error message. Could you fix my code?

The csv data is attached.

The code is below:

opts = delimitedTextImportOptions("NumVariables", 11);
opts.DataLines = [2, Inf];
opts.Delimiter = ",";
opts.VariableNames = ["v1","v2","w1","w2","u1","u2","LL","L1","R","eta","vl"];
opts.SelectedVariableNames = ["v1","v2","w1","w2","u1","u2","LL","L1","R","eta","vl"];
opts.VariableTypes = ["double","double","double","double","double","double","double","double","double","double","double"];
opts.ExtraColumnsRule = "ignore";
opts.EmptyLineRule = "read";
tbl = readtable("https://de.mathworks.com/matlabcentral/answers/uploaded_files/1144220/data.csv", opts);

v1 = tbl.v1;
v2 = tbl.v2;
w1 = tbl.w1;
w2 = tbl.w2;
u1 = tbl.u1;
u2 = tbl.u2;
LL = tbl.LL;
L1 = tbl.L1;
R = tbl.R;
eta = tbl.eta;
vl = tbl.vl;

clear opts tbl
x = sym('x',[24 1]);


eqn= w1(1:24).^(1./eta(1:24)).*((v1(1:24)+vl(1:24).*(x-L1(1:24)))./(u1(1:24)))==w2(1:24).^(1./eta(1:24)).*((v2(1:24)-vl(1:24).*x)./(u2(1:24)))

eqn = 

solx = vpasolve(eqn,x)

solx = struct with fields:
     x1: 39849.098439839888039995580252118
     x2: 31896.131131835614248409660424623
     x3: 30623.46859228488599788098808533
     x4: 34288.357365128718164252084030317
     x5: 33218.449588363269704310607329214
     x6: 38683.838907884258366654183935849
     x7: 48498.709829085994064528936869907
     x8: 53734.835565915578538534431637503
     x9: 60971.254678305479099782365418956
    x10: 60795.578490308419439506465520588
    x11: 63598.645068871610104964068769523
    x12: 73805.83241708308175855439464272
    x13: 93493.202580227088226990711316688
    x14: 92395.482938456487295586853293179
    x15: 88114.171897603740990721877865897
    x16: 94710.58237067927806753793595844
    x17: 95519.94075011699982930537150245
    x18: 104692.3361253001772882836097709
    x19: 114727.61054921550579417687813943
    x20: 105868.47733825101949217215380698
    x21: 122616.33829033540168661425772284
    x22: 111089.51657475909520158536228558
    x23: 115853.95267280550435053918951603
    x24: 147912.82705953864516362058769025

[Jan]

Whenever you mention an error message, post a copy of the complete message. It is easier to solve a problem than to guess, what the problem is ;-)

[Deokjae Jeong]

@Jan, sorry about that.

There is not any error message, but it just gives solution as below, which is empty.

solx =

struct with fields:

x1: [0×1 sym]

x2: [0×1 sym]

x3: [0×1 sym]

x4: [0×1 sym]

x5: [0×1 sym]

x6: [0×1 sym]

x7: [0×1 sym]

x8: [0×1 sym]

x9: [0×1 sym]

x10: [0×1 sym]

x11: [0×1 sym]

x12: [0×1 sym]

x13: [0×1 sym]

x14: [0×1 sym]

x15: [0×1 sym]

x16: [0×1 sym]

x17: [0×1 sym]

x18: [0×1 sym]

x19: [0×1 sym]

x20: [0×1 sym]

x21: [0×1 sym]

x22: [0×1 sym]

x23: [0×1 sym]

x24: [0×1 sym]

Answer 1

[Torsten]

Take ^(1/eta) of both sides of the equations. You get linear equations in x. Solve them.

See solution above.

[Deokjae Jeong]

umm,.. it gives the same problem.

[Torsten]

What problem ? The solutions are listed above ...