# Jim Riggs

### Missile Defense Agency - Advanced Technology Group

Developing simulations for the Missile Defense Agency - Advanced Technology group. 30+ years experience in missiles, smart munitions and other aerodynamic systems.

**Programming Languages:**

Python, C++, C, MATLAB, Fortran

**Statistics**

RANK**162**

of 271,614

REPUTATION**655**

CONTRIBUTIONS

**4** Questions

**251** Answers

ANSWER ACCEPTANCE **
75.0%
**

VOTES RECEIVED**136**

RANK

of 18,318

REPUTATION**N/A**

AVERAGE RATING**0.00**

CONTRIBUTIONS**0** Files

DOWNLOADS **0**

ALL TIME DOWNLOADS**0**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Content Feed**

Seconds, minutes or hours for year-long SIMULINK simulation?

There is a great risk of somthing going wrong if you use anything other than seconds in a physics model, since, as you pointed o...

2 days ago | 1

| accepted

How to initialise Goto variables used in enabled subsystems

You should not need to "initialize" the Goto variables. The "Goto / from" blocks are simply a way to connect a signal without s...

8 days ago | 0

| accepted

I need help writing a function with one input and one output

The syntax for defining a function is: function steps_made_sucessfully = walk(commanded_steps) % insert your code here % ... ...

20 days ago | 0

Generate look angles between aircraft and satellite

I don't think that you will find this exact problem solution in the Aerospace toolbox, but it does contain some functions that y...

22 days ago | 0

Simulink generate input at begining of simulations

I am not sure that I understand your specific question (i.e. the implementation you are describing). The way it sounds to me, y...

22 days ago | 0

Not able to Understand Code for "Volume of Solid by Revolution"

[X,Y,Z] = cylinder(fx(xivals)-yr,100); Creates a set of 3D points that define a cylinder figure('Position',[700 200 560 420])...

23 days ago | 0

| accepted

Why should I use operation blocks instead of a quicker function block in simulink?

You might want to check out this documentation on Comparison of Custom Block Functionality. It references some limitations on M...

28 days ago | 0

How to save a data in another folder?

I like to define a string defining the work folder; e.g. workfolder = 'C:/user/JR/projectName/' save([workfolder 's1.mat'], ...

28 days ago | 0

| accepted

How to run a for loop one at a time with each button click?

At the end of your "for" loop, add a "while" loop that looks for the button value. if i < 3 (you don't want it to pause the l...

29 days ago | 0

How can I access both data and time from the running simulink model and use it in a particular program?

Simulink has a "to workspace" block which saves the time history of the model data to the Matlab workspace in a variable that yo...

1 month ago | 0

How to create a loop with unknown number of iterations?

What you are describing sounds like a "while" loop. You specify a logical condition which will terminate the loop i=0; condit...

1 month ago | 0

How can I plot two functions in the same graph?

Try this: fplot(@(x) cosh(x)); hold on fplot(@(x) 0.6671x^3-1.7921x^2+2.7580x-0.089);

1 month ago | 0

Transformation matrix between two cartesian systems

Coordinate rotation (or transformation) involves expressing the coordinates of a point defined in one reference frame in terms ...

1 month ago | 1

| accepted

Issue with doing FM on SIMULINK

1) The error is generated because the integration block is a continuous block, and you have specified a discrete solver. Change...

1 month ago | 0

| accepted

Constant block doesn't accept array

Yes, you can save the value to the workspace and reference it in a constant block. As @Paul points out, the label on the Goto b...

1 month ago | 1

How to add x and y variables to individual values after creating a heatmap.

You can modify the axis properties after creating the plot: ax = gca; % get the curent axis handle ax.XTickLabel = {'Jan','Fe...

1 month ago | 0

| accepted

draw rod shape trajectory

You might want to give this a try: Plot3 Shaded Line

1 month ago | 0

How to change my Simulink Scope output at workspace from 1x1x284 double to 284x1 double.

Try using the "reshape" command. There is also a reshape block in Simulink.

1 month ago | 0

For-loop using only last iteration

Inside the loop C = zeros(1,10) + A; the function "zeros(1,10)" is assigning zeros to the entire C vector, then adding A. Als...

1 month ago | 0

How can i merge the signals from the sensors into 1 signal ?

The merge block is not used to combine signals - it is used to select one of two triggered signals. The two inputs are signals ...

1 month ago | 0

Output for Accelerator Model

I think there is a misunderstanding. The way I read it, if you use a large number of inport and outport blocks (at the root lev...

1 month ago | 0

| accepted

What kind of numerical method is used for the inverse kinematic block at simulink?

Here is a link to the Matlab documentation: Inverse Kinematics Algorithms

2 months ago | 0

| accepted

Hold a value indefinitely once a condition becomes true

Try This:

2 months ago | 0

| accepted

Trying to plot array points on a graph.

You might also try this: [row,col] = size(AA); % AA is the data matrix figure; for ii=1:row for jj=1:col if ...

2 months ago | 0

How to connect the two signals in one signal in MATLAB Simulink? I mean first signal finishes second signal starts.

You description of the problem is confusing to me, bu the statement in the title "first signal finishes second signal starts" ...

2 years ago | 0

Numerical Integration in Matlab

There seem to be two problems: 1) your function "fun" returns "NaN" at zero, so you cannot integrate starting from zero. You n...

2 years ago | 0

| accepted

Simulink counter block having an initial starting value of -1

Yes, the two counter blocks in the library do not allow you to set the initial value. Whenever I need to use a counter, I usual...

2 years ago | 1

| accepted

Finding the roots of an equation using Newton-Raphson method but I don't know the equation!

You use a numerical approximation for the derivative. Start at some initial guess for x & y. take a small step, and compute th...

2 years ago | 1

Implementing Angles as an input in Simulink

It appears (based on the icon on the block) that the block labeled "Robot Controler" is a Matlab function block. In order to a...

2 years ago | 0