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16h
comment How to count the integer grid numbers defined by inequalities?
@BobHanlon Thanks, I knew there must have been a better way.
18h
revised How to count the integer grid numbers defined by inequalities?
deleted 2 characters in body
18h
answered How to count the integer grid numbers defined by inequalities?
21h
revised How to tell NDSolve about known relations of the exact solution
added 253 characters in body
1d
comment Non-linear curve fitting with multiple parameters and conditional expression
Please post Mathematica code, not pictures. One first thing is : in your definition use g[T_].
2d
revised How to tell NDSolve about known relations of the exact solution
added 5 characters in body
2d
answered How to tell NDSolve about known relations of the exact solution
Aug
19
comment Mapping data on Archimedes' spiral
Maybe changing your data to Sqrt[2 #] & /@ Table[{i, i}, {i, Range[0, 1/2 20^2, 1/2 20]}] or similar ?
Aug
19
comment Plot range of a 2-dimensional function as a function depending on one variable
You can add any of If, Piecewise, Boole and more to your definition of myFunc.
Aug
18
comment Making a conjecture concerning a certain upper-triangular matrix
You can let Mathematica do the work with Simplify[Sum[ Sum[Boole[i <= p] Boole[p <= q] Boole[q <= j], {p, 1, n}], {q, 1, n}], Assumptions -> {(i | j | n) \[Element] Integers, i <= j, i <= n, j <= n}].
Aug
18
reviewed Close How can I plot weather data?
Aug
16
comment Testing a package in Mathematica 9
Have a look at the Workbench.
Aug
12
comment Optimization in Mathematica
Could you provide a small example ?
Aug
5
comment How do I plot the differential of this function?
You can do z[x_,y_]=ComplexExpand[..., TargetFunctions->{Re, Im}].
Aug
5
comment How do I plot the differential of this function?
One issue is that you defined z as an expression but you're using it as a function. Another issue might be the derivative of Abs; try using ComplexExpand.`
Aug
5
answered how could I repalce Sqrt[x^2+y^2+z^2] back to r
Aug
4
comment How to extract only real solutions from the result of Solve
For all Solve, Reduce, NSolve you can specify a domain for your unknowns, Reals in your case.
Aug
2
comment Series expansion for $\frac{x}{1- \frac{1}{x}}$
You can add //Normal after Series[...]; however is this an expansion for small or for large x ?
Jul
27
comment How do I exclude the vertical line plotted at a discontinuity?
A starting point is ContourPlot[function + 2*y == 1, {x, 0, 1.5}, {y, 0, 1.5}, PlotPoints -> 100, Exclusions -> {1/function == 0}].
Jul
24
comment Finding a root of a parameterized integral
f[a_?NumericQ] := Integrate[ BesselJ[0, x - a] BesselJ[0, x + a], {x, -[Infinity], [Infinity]}] and then FindRoot[f[a], {a, 0.5}] ?