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# Jim Riggs

### Missile Defense Agency - Advanced Technology Group

227 2017 이후 총 참여 횟수

Developing simulations for the Missile Defense Agency - Advanced Technology group
30+ years experience in missiles, smart munitions and other aerodynamic systems. Specializing in systems engineering, aerospace systems design, simulation and modeling, aerodynamics, and numerical analysis.

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how can i resolve this equation Runge kutta method
Ths is the equation for a parabola. y'' = -1 y' = -y y = -1/2 y^2 No need for a numerical approximation.

1일 전 | 0

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Missile Lauch friction gamma factor - Output deviating from desired output, please help!
Step 1: Draw a free body diagram that shows the body with all of the forces that act on it and the coordinate frame(s) that are...

3일 전 | 0

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How to calculate the slope from geopraphical coordinates?
First of all, you should consider the relationship between the WGS84 lat/lon/alt and the ECEF frame. Altitude is perpendicular ...

5일 전 | 1

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calculate rotation matrix in 3D
I'll assume that we make the reference frame right-handed by negating the axis_3 vector such that axis_1 = [2.7239 -0.2014 -...

15일 전 | 1

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Translational motion of a rotating object.
To begin, Chasles' theorem states that translational motion and rotational motion obey the law of superposition. Therefore, you...

23일 전 | 0

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change variable value based on other variable in if loop
Your input command is requesting a string input: in1 = input('first: ','s'); in2 = input('second: ','s'); This results in in1...

23일 전 | 1

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I don't know the problem involved Backward difference.
I am assuming that your question is that you don't understand Simpson's rule. Below is an exerpt from Wikipedia: Simoson'...

약 1달 전 | 0

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1-2-1 or X-Y-X rotation matrix not supported
I recently cataloged all of the permutations of the 2 and 3 axis planar rotations. It is easy to write your own functions. See...

약 1달 전 | 0

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Extracting data from simout MATLAB work space
simout is a timeseries structure. I like to extract separate vectors from the structure, for example: t = timout.time(simout.t...

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Where can I publish Matlab-compiled software?
If you want to share the source code, you can post it on Matlab File Exchange

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In my Simulink model I would like to conditionally write output data to selectable .mat files in different relative directories.
This sounds like a rather sophisticated way of constructing output. I'm not sure if that is easily acomplished with the "to fil...

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minimum feret diameter of particle
https://blogs.mathworks.com/steve/2018/02/20/minimum-feret-diameter/?s_tid=answers_rc2-1_p4_MLT

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Vlookup equivalent function for matlab
If your data is in a 2D table (matrix) and you want to locate a column that matches the exact value from another column, then lo...

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How calculate the second and third numerical derivative of one variable f(x)
The Matlab "diff" function is basically the Backward difference formula. There are much more accurate ways to compute numerical...

약 1달 전 | 0

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Runge kutta order 2 by hand
In the statement Y(1) = [t(1);y(1)] the simi-colon ";" indicates you are attempting to put 2 rows of numbers into a single ro...

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Correct way to detect Zero crossing
A thought you might want to consider: if you multiply the current value, y(i) by the previous value y(i-1), this product is on...

약 1달 전 | 1

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How to add optional outport to simulink model?
You can use a switch to select between the two different output options that you want, and there are a number of ways to activat...

약 2달 전 | 0

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Ralston's method function
There is an error in your function in the k2 term. For Ralstons method, it should be: k1 = h*f(t(i), y(i)); k2 = h*( f( t(i) ...

약 2달 전 | 0

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First and Second Order Central Difference
For starters, the formula given for the first derivative is the FORWARD difference formula, not a CENTRAL difference. (here, ...

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How can I integral Acceleration-time data to Velocity with removing drift?
It seems that what you are asking cannot be done. More information is needed. In order to remove an error in the data, you nee...

약 2달 전 | 1

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circle with three points
Try this.

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Unit step function explanation
Double is simply the data type , i.e. double precision. (T>=0) is a logical 0 or 1. double converts the answer to double preci...

약 2달 전 | 1

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Solving Linear System of Equations with a Real Parameter
Using the symbolic toolbox, you can solve it as follows: 1) Define symbolic quantities; syms A B x1 x2 x3 x4 lamda 2) Write t...

약 2달 전 | 1

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Not sure why vector changes assignment when using ode45
I dont think that the statement out3=(3,1) is a valid statement. It may be that out3 is not the size that you intend. try o...

약 2달 전 | 1

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Why ,the quaternion values from sensor fusion toolbox are switched ?
There are two different ways that are commonly used to represent quaternions. Q = [a,b,c,d] with d being the scalar part, and a...

약 2달 전 | 0

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Euler's method for two first order differential equations?
Try preallocating x and y nsteps = (b-a)/h + 1; % this is the number of elements in t(a:h:b) (It is = N+1) x=zeros(1,nsteps);...

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How do i create a projectile?
Always start by making a drawing of the problem. Define the coordinate system (which way is positive/negative) What are the pa...

약 2달 전 | 0

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Error - Undefined function or variable
Line 16: if epsc<=eps0 Variable epsc is not defined.

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two body problem using ode45
I have studied the 2-body problem and the accuracy of different numerical solutions. See my comments in this thread: Discussi...

2달 전 | 1

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All sample times for this block must be discrete. No continuous or constant sample times are allowed
On the Simulink toolbar, select "Display" - "Sample time" and check "all". This will show the sample time for all of the signa...

2달 전 | 0

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