Recent content by Unrest

  1. U

    MATLAB Matlab - can't even do a simple arithmatic

    Every system has its limits. If you want to use it at its limits then you should understand what they are. Expecting 20 significant figures of accuracy from double precision floating point is asking it to go beyond its limits. Those errors are inherent in how floating point numbers in...
  2. U

    MATLAB Matlab, Three Dimensional plot of three charges

    What approach would you take in C++? This looks like something that could be done with the finite element or finite difference (?) method. But I guess there's an easier or analytic way you have in mind. Conceptually Matlab isn't much different from C++, just without the objects (I think?)...
  3. U

    MATLAB MATLAb creating variables from ascii document

    I'm pretty sure there's an easier way. A command that does it in one hit. But I forget.
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    MATLAB Matlab error message needs help

    This is a complete stab in the dark. But my wild guess is that the software is creating a temporary batch file (Nov20....bat) and then trying to run it. When it tries to run it, the file isn't there. It could be not there because some unreported error ocurred while trying to create it. or it...
  5. U

    DOUBT in numerical integration

    Oops I didn't see the title of you message. In that case there must be something wrong with your Matlab code since it should be able to integrate anything it can evaluate. Could you paste the code, including the limits of the integration? Seems like a function that can easily be numerically...
  6. U

    Find mappings between two surface meshes (for morphing)

    No. I don't want to interpolate. Actually I already have linear interpolation working fine. I want to find out which points to interpolate between. Most sets of pairs of points will produce a random tangle. I want to find, for example only those 6 sets shown in the picture. Currently I...
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    Can anyone solve my PDE equation?

    I don't really know. But if you categorize it by order, linearity, homogeneity, etc. then you can look up techniques for solving that particular type of equation. Oh, solve2? Are you using some software? Which software?
  8. U

    IF loop within a FOR loop problem

    You want to update cpto each iteration, and use that updated value in the next iteration? Why is cpto an array? Why not a single value that changes every iteration? Do you need to keep track of all the previous values? Either way, you can update cpto at the end of the loop and the new value...
  9. U

    DOUBT in numerical integration

    Are you trying to do numerical or symbolic integration? Maybe that's a function which has no analytic integral? If numerical, what are the limits?
  10. U

    Find mappings between two surface meshes (for morphing)

    Thanks chiro However, interpolation isn't my problem. I intend to simply use linear interpolation despite its problems. It's the stage before interpolation that I'm stuck on. How can I find the pairs of vertices to interpolate between? In my example there are 6 possible sets of...
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    Find mappings between two surface meshes (for morphing)

    I want to morph two surface meshes made from triangles and quadrilaterals. They are already "compatible" so that one can be converted to the other simply by changing the coordinates of the vertices. No vertices, gaps, edges, etc. are created or destroyed. Not sure of the terminology. I think...
  12. U

    Programming for Engineers!

    I want to have a little rant about this and hope you don't go down the dark path so many have gone before. If you want to write software that anybody else might use, or if anybody else might want to read/modify the source code, then you should look at software engineering too. UIs are also...
  13. U

    Force transmitted by engine

    You mean torque? power = torque * angular velocity. There may be peaks above that because of the non-constant torque produced by an engine.
  14. U

    Would open or flanged ball bearings be better for this application?

    You need to work out the thrust (axial) load as well as the radial load, and find bearings that can support them. Also consider misalignment and speed. Try SKF's site, it has pretty comprehensive tools to select a bearing. The ones with the covers can have grease retained in them. If it's open...
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    Trying to design a robotic joint.

    Because of the limited range of motion, you could also use a big pulley with a steel wire or chain fixed to it. Wind the other end of the loop around a drum on the servo/motor. If you're not worried about speed you could also put a counterweight on the arm and that eliminates the torque...