EGR 103/Fall 2009/Questions

Lab 5

• I am making a graph for NormDist.m as part of Lab 5, but I cannot get NormDist to accept a non-square matrix of z values. It treats linspace(-4, 4, 100) as a 100 x 1 matrix. Any hints for how I can graph NormDist? Mjc43 13:46, 12 September 2009 (EDT)
  • It's treating it as a 1 x 100 matrix - and that is correct; be sure to use .* and ./ and .^ in your calculation and it will be fine. DukeEgr93 14:42, 12 September 2009 (EDT)

• On Problem 5.4.3, I typed in the Manning equation as

  U = (sqrt(S)./n)*((B.*H)/(B+2.*H))^(2/3)
  

  which failed to produce a graph. What is the reason for this?—Preceding unsigned comment added by Xyz2006tor (talk • contribs)
  • That just calculates a value - you have to use the plot command to create a graph. DukeEgr93 00:40, 17 September 2009 (EDT)

• how do I find the most displacement for a million values? I've run it for like 25 minutes and matlab is still busy. Ruobling 17:09, 17 September 2009 (EDT)
  • The min command certainly should not take that long, even for 1 million values... Is it waiting for you to hit return? DukeEgr93 15:25, 19 September 2009 (EDT)

• Several of my functions are receiving an error message saying, "??? Undefined function or method 'NormDist' for input arguments of type 'double'." I've checked to make sure that the function and the m-file have the same name, but I'm not sure what else to do. I think it might have to do with my if-trees? JCRankin 17:39, 19 September 2009 (EDT)