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  • Users: mapi
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  1. mapi

    gray color for bar in the bar plot

    Hi, How to plot gray color for a set of bars and white color for another set of bars? And also, how to put legend on? Thanks, mapi
  2. mapi

    one-way anova with non-integral DOF

    I have group mean, 95% uncertainty (not std) and degrees of freedom (not integral) for each group. How do I compare the means? It seems that anova1 is not applicable. Thanks.
  3. mapi

    when capacitance depends on voltage, how to calculate impedance

    For a simple circuit with only one capacitor C, when C is constant, the impedance is Z(w)=1/jWC. But when C is dependent of the voltage, C(V), then what is the impedance? Thanks, Mapi
  4. mapi

    statistics on experimental results---need help

    Hi, Data A from group 1 and B from group 2. Now mean(A) is larger than mean(B). We want to compare the two groups: In Matlab, ttest2 is used: To test if A is greater than B: p=ttest2(A,B,0.05,'right') give p=0.045<0.05, so mean of A is statistically greater than mean of B. To test if...
  5. mapi

    the range in xlswrite function??

    xlswrite(filename, M, sheet, 'range') E.g., the 'range' can be 'B2:G5'. Can we rewrite the range as 'Bnum_1:Gnum_2', where num_1=2 and num_2=5? Thanks, Mapi
  6. mapi

    anybody know the difference between filter and filtfilt

    Hi, I want to filter some experimental data: y=f(x),---smooth the y values. But I have tried both filter and filtfilt, what is the difference between them? Or which one is better? Mapi
  7. mapi

    about standard deviation in ttest

    Hi, I have a question about the calculation of standard deviation in ttest. From matlab help, ttest uses the sample standard deviation which is the total squared error divided by (n-1). From wiki, it says the grand standard deviation of sample is used (divided by n or n-1?). Are the two...
  8. mapi

    algorithm of gradient?

    What is the algorithm of gradient? FX=gradient(F,x); FX(i)=(F(i+1)-f(i-1))/(x(i+1)-(i-1))?? How about FX(1) and the gradient at the last point? Thanks, Mapi
  9. mapi

    How to get slope of discrete data

    Hi, I have discrete data which can be some kind of curve. Now if we don't use a function to fit the data, and just based on these discrete data, can we get the approximate slope? Thanks.
  10. mapi

    how to measure the length of curve with Matlab?

    Hi, I have a picture with a curved body. Now I need to get the length of some curves on the body. How to do that with Matlab? One thing to do is to determine the mask of the curve and thus the coordinate on this curve. Anybody knows how to do it? Thanks, mapi
  11. mapi

    books for composite with more than 2 components??

    Hi, I am looking for books/review papers that deal with composites with more than 2 components, say, matrix, fibres, and other stuff. Can anyone recommend good ones? Thanks, Mapi
  12. mapi

    cross-ply laminate twisting issue-help

    Hi, Here is a two-layer laminate (0 degree/90 degree, same thickness, in x-y plane), and it is only subjected a uniaxial loading at x-direction. As a result, the laminate will twist from the calculation by using the constitutive realtion: curvature Kx is not zero, and curvature Ky is zero...
  13. mapi

    Numerical singularity issue

    Hi, I encouter a problem. In msg file, it says: SOLVER PROBLEM. NUMERICAL SINGULARITY WHEN PROCESSING NODE 191 D.O.F. 3 RATIO = 6.85800E+11 I wonder what can cause such singularity problem and I don't know what is wrong with my UEL code. Thanks.
  14. mapi

    How to know actual nodal number in UEL

    Hi, In UEL, Abaqus, we don't know the actual nodal number in the element, right? For example, one element has the following four nodes: 3, 4, 5, 8. Then in UEL, COORDS(1,1) denotes the coordinate of first degree of node #1, that is node with actual number 3. Now I want to know the actual...
  15. mapi

    negative eignevalue issue

    Hi, The msg files say that the matrix has negative eigenvalues. But it also continues to solve the problem. And it finally gives right result. So my questions are: 1)what heppens? Is the matrix not constructed correctly? 2) Even, the matrix has negative eigenvalues, is the result that...
  16. mapi

    error:unable to delete files

    Hi, I first run: abaqus job=job-name user=uel datacheck, and it passed. Then I run: abaqus job=job-name user=uel interactive Abaqus error: unable to delete files: job-name.mdl,job-name.stt,job-name.023. Please check that you have file owership and premissions for removal. BTW,I use the...
  17. mapi

    generate fortran code with Mathematics

    Anybody are experienced in generating Fortran code with Mathematics. I just want to know how complex of the problem the Mathematica can deal with. Say, I have a function (not simple polynomial) and I want to calcualte the value of the function and its derivative upt to second order. Thanks, Mapi
  18. mapi

    How to write makefile if use IMSL library

    Hi, I am going to run my fortran code in a server and I need to write a makefile. Now in my fortran, I invoke the subroutine in IMSL. So how do I write the makefile? or how to define the IMSL subroutine in makefile? Thanks, mapi
  19. mapi

    the accuracy number

    Hi, When I look at the result (e.g. displacement), there is only four digital number. How can I get more number? Thanks.
  20. mapi

    two questions in UEL.for

    In a user-element subroutine: Does MLVARX=NDOFEL? Why does RHS(MLVARX,*) use MLVARX other than NDOFEL? At the beginning of the UEL-name.for,the setting of RHS(*,*)=0 is from k1=1 to NDOFEL (not MLVARX). Do we have to set RHS(*,*) and AMATRX(*,*) to be zero for all kinds of problems at...

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