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Jul
25
comment notebooks not opening in mathematica 10
Why do not you ignore this message, especially, since you know that no content is dangerous?
Jul
25
comment substitute definition when exponents are involved
Generally speaking if f=f(R), where R=r-r0 and f'=df(r)/dR. Then Grad[f]=f'*Grad(R). And Grad(R)={(x-x0)/R,(y-y0)/R,(z-z0)/R}. That is the answer: Grad[f]=f'(R)*{(x-x0)/R,(y-y0)/R,(z-z0)/R}. What are we discussing here about?
Jul
24
answered substitute definition when exponents are involved
Jul
24
comment How to solve an operator form of an integral equation by iteration method?
Together with the code I suggest that you explain, why do you solve the integral equation instead of the differential, especially accounting for the simplicity of the latter.
Jul
24
answered How to draw a plane parallel to one of the coordinate planes?
Jul
24
answered Finding a root of a parameterized integral
Jul
24
comment How to use this Lorentzian function fit my data, I tried NonlinearModelFit, it always resulted with an error
@Hang Yang First the answer to your first comment: I tried Lorenzian first. In particular, the same type of the model as in the answer of blochwave. It worked poor for me. I see from the answer above that there is a trick giving the solution. However, my experience of fitting shows that the necessity of tricks may mean that the data is poorly described by the model used, and another model should be looked for. That motivated the function I applied. The second question: I did not optimize the model. For example, why k=0.75? It is up to you, if you decide to use this model.
Jul
23
answered How to use this Lorentzian function fit my data, I tried NonlinearModelFit, it always resulted with an error
Jul
23
comment What is wrong with ContourPlot
It is just a cut-off. Try to add the option PlotRange -> {0., 0.3}.
Jul
23
answered List of Coefficients of Expression with symbolic Terms
Jul
23
awarded  Nice Question
Jul
22
comment Mathematica Solve function does not solve double exponential
@JosGranada Continuation. The answer to this question (i.e., how to solve it) depends upon the answer to the question, what do you intend to do with the solution. And I do not know that. As an example of what can be done I have drawn it using ParametricPlot3D function. You can check it in Menu/Help/Documentation Center/Parametricplot3D. If you have in mind some other use of the result, specify it.
Jul
22
comment Mathematica Solve function does not solve double exponential
@JosGranada Continuation. variables and parameters: Y=Exp[f], x=-b*Log[y], y=A*z, where A = (c/a)^(-(d/(b - d))). This transforms the equation into its form k + z + z^p == 0, where kand pare given in my answer in the explicit form. All this I did using Mma, but you may do also by hand, no problem. Then the question arises, how to solve this equation. If p is Integer and below 5 it is easily solved by Mma exactly. However, if it is not the case, (That is p is an arbitrary real number) this equation is much simpler that the initial one, but it is in no case trivial.
Jul
22
comment Mathematica Solve function does not solve double exponential
@JosGranada The #&form is a pure function. Check this term in Menu/Help/Documentation Center. The construct Divide[#,x]&[z] returns z/x. In combination with Map like this: Map[Divide[#,x]&,expression] it projects the division over xoperation onto all elements of the first level of the expression. However, if you are only few days user of Mma, this may also sound obscure. What you can do wile you are not that familiar with Mma is the following. First with all those Mma operations I did a rather trivial rescaling of your equation. It may be summarized by the following changes of
Jul
21
asked Report: IgnoringInactive: a bug?
Jul
21
comment How to enter chemical equations?
@Sjoerd C. de Vries, continuation. It makes 2 in H2O indeed the full size, but H and O are still Italic. Have you a solution for that?
Jul
21
comment How to enter chemical equations?
@Sjoerd C. de Vries This might be made without changing the StyleSheet, just for a certain cell. The advantage is that the text may contain not only chemical symbols, but also usual mathematical expressions that should be italic with smaller sub- and superscripts. This is clear. The problem arises, however, if one wants to type a chemical formula inside an inline cell that is embedded into a text cell. This is very often the case that I meet. I tried to put into this cell Ctrl+Shft+E/ SingleLetterItalics->False and ScriptSizeMultipliers->1 /Ctrl+Shft+E.
Jul
21
answered Mathematica Solve function does not solve double exponential
Jul
21
answered How to combine the sum of two rational polynomials into a single rational polynomial
Jul
16
asked ParametricRegion question - a bug report