Recent content by peterjaybee

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    Isotropic average of a cosine function

    Hi, please look at the following equation. \frac{3}{16}\frac{\nu_{Q}^{2}}{(1+K_{iso})\nu_{0}} \left(\frac{7}{2} \cos^{4}\theta - 3\cos^{2}\theta + \frac{5}{6}\right) In the paper I am reading, this is simplified considering the isotropic average of a cosine function to...
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    Irreversibility temperature in superconductors

    Hello, I would be grateful is someone could explain what the irreversibly temperature in type II superconductors is. I have just done some NMR experiments on MgB2 and get a lineshape change at the the irreversibility temperature as opposed to the field corrected Tc, so I believe it has...
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    Is there a guide to using the density matrix formalism in quantum mechanics?

    I ask because bra's and ket's seem to behave in a similar manner to co-varient and contra-varient vectors. I guess this is not a coincidence.
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    Is there a guide to using the density matrix formalism in quantum mechanics?

    Hello, I am looking for a guide to quantum mechanics and the density matrix formalism which uses the Einstein summation convention. Does such a guide exist?
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    MATLAB Access Variable in MATLAB Structure Using User Input

    Hi I am trying to use MATLAB for some data analysis. I start by getting user input for a variable called exptno, Then I want to access a location in a structure, but to do this I need to append the variable exptno to the name of the structure. Ill try and give an example to hopefully make it...
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    NMR Spin-evolution simulations

    Thanks, ill have a look
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    Atlab I am trying to write a script and currently I save a matrix

    Hi, in MATLAB I am trying to write a script and currently I save a matrix to a .txt file using save('expt1.txt', 'table', '-ascii'). 'table' is the matrix I want to write to file. This works fine, but I would like to make the file name to be 'exptn.txt', where n is a variable specified...
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    Rearranging y(x) = a + bx^{-2} + cx^{-4} + dx^{-6} to Find x

    Thanks for your reply. What numerical technique would you suggest?
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    Rearranging y(x) = a + bx^{-2} + cx^{-4} + dx^{-6} to Find x

    Hi, I have fitted a graph with a function of the form y(x) = a + bx^{-2} + cx^{-4} + dx^{-6} I now need to calculate x for a given y and have no idea how to go about rearranging this function. I need to find x for a lot of y values, so I was hoping to write something in methematica, but...
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    C/C++ What is the issue with multiplication in my C++ program?

    Oh ok. Pretty sneaky way around the problem. I like it!
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    Test Prime Numbers - Peter's Program

    What are the python indentation rules
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    Test Prime Numbers - Peter's Program

    Hi, I'm new to programming and have written the following code to test for prime-ness, but it doesn't seem to work except for n = 3. I think it may have something to do with my goto statement. Can anyone see a way of avoiding this or any other errors with the program? #include...
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    C/C++ What is the issue with multiplication in my C++ program?

    I have never seen this type of code before, but it works! What does the -'0' do? Many Thanks, Peter
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    C/C++ What is the issue with multiplication in my C++ program?

    For example once the program is run for the nhs number 1234567890, I get the following initial output. Current running total is 0 NHS number element 0 is 1 weighing factor is 10 NHS number digit 0 x the weighing factor is 490! this should be 1 x 10 = 10
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    C/C++ What is the issue with multiplication in my C++ program?

    Hi, I am having an issue with multiplication in C++. I am writing a program to check the validity of an NHS number. To do this I must; multiply digit 1 of the NHS number by 10, multiply digit 2 of the NHS number by 9, multiply digit 3 of the NHS number by 8 ...etc The answer from each...
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