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.

Answered

Why is my code not working?

Not entirely sure if this is the reference in the error message, but this line has unballanced parentheses: f = (1/(t-t^(-1))*...

Why is my code not working?

Not entirely sure if this is the reference in the error message, but this line has unballanced parentheses: f = (1/(t-t^(-1))*...

23 dagar ago | 0

Answered

SIR Simulink Model Function Block

In the Simulink library browser, on the "sources" pallet, you will find a "clock" function. Use this to create a time signal. ...

SIR Simulink Model Function Block

In the Simulink library browser, on the "sources" pallet, you will find a "clock" function. Use this to create a time signal. ...

2 månader ago | 0

Answered

How can one do this calculation?

Look into using logical indexing. Not my strong point, but for example, if A is the 3 x 10 matrix, you can select all cases whe...

How can one do this calculation?

Look into using logical indexing. Not my strong point, but for example, if A is the 3 x 10 matrix, you can select all cases whe...

3 månader ago | 0

Answered

Kalman Filtering for smoothing GPS speed data

The problem is with this line: P = (1-KG)*P; This causes the gain P to continuously decrease. After a while, the gain P is ve...

Kalman Filtering for smoothing GPS speed data

The problem is with this line: P = (1-KG)*P; This causes the gain P to continuously decrease. After a while, the gain P is ve...

4 månader ago | 1

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Answered

numerical derivate and central difference

Here are some Numerical difference formulas using the central difference method (substitute dt = h). You can find more formulas...

numerical derivate and central difference

Here are some Numerical difference formulas using the central difference method (substitute dt = h). You can find more formulas...

5 månader ago | 1

Answered

Meaning of the following: function [y1,...yn] = input()

It simply means that there are no user inputs to this function. The long list of variable names are returned from the function....

Meaning of the following: function [y1,...yn] = input()

It simply means that there are no user inputs to this function. The long list of variable names are returned from the function....

6 månader ago | 0

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Answered

Angle Between two vectors.

Given two vectors A and B, the dot product of the two vectors (A dot B) gives the product ABcos(ang), so to get just the angle, ...

Angle Between two vectors.

Given two vectors A and B, the dot product of the two vectors (A dot B) gives the product ABcos(ang), so to get just the angle, ...

6 månader ago | 0

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Answered

Is it possible to summarize this code?

You could use a switch case structure, that would be a bit more compact. it would look like this: switch davar1.CC_CHECK ...

Is it possible to summarize this code?

You could use a switch case structure, that would be a bit more compact. it would look like this: switch davar1.CC_CHECK ...

6 månader ago | 2

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Answered

help fixing the Heuns method

Heun's method is otherwise known as "explicit trapezoidal method", "improved Euler's method" or "modified Euler's method". Th...

help fixing the Heuns method

Heun's method is otherwise known as "explicit trapezoidal method", "improved Euler's method" or "modified Euler's method". Th...

7 månader ago | 0

Answered

I need help coding a human cannonball ignoring air resistance

Assuming zero drag and relatively low muzzle velocity ( acceleration due to gravity = constant), the point-mass trajectory can b...

I need help coding a human cannonball ignoring air resistance

Assuming zero drag and relatively low muzzle velocity ( acceleration due to gravity = constant), the point-mass trajectory can b...

7 månader ago | 1

Answered

Runge Kutta 4th Order Method

I think the problem is the T argument. in k1 you have a capital T, which is a 3-vector in k2, k3, and k4 it is a lower case t,...

Runge Kutta 4th Order Method

I think the problem is the T argument. in k1 you have a capital T, which is a 3-vector in k2, k3, and k4 it is a lower case t,...

8 månader ago | 0

Answered

Matlab Homework that im struggling with

To prompt a user to enter a value, try: x = input('Enter the number of equations (from 2 to 5): \n')

Matlab Homework that im struggling with

To prompt a user to enter a value, try: x = input('Enter the number of equations (from 2 to 5): \n')

8 månader ago | 0

Answered

I need help with this script

Try this: T = input('Enter your temperature') if T<=96 disp('You are either hypothermic or a zombie') elseif T<99 d...

I need help with this script

Try this: T = input('Enter your temperature') if T<=96 disp('You are either hypothermic or a zombie') elseif T<99 d...

8 månader ago | 0

Answered

Ballstic Impact of Bullets on armor

I don't know af any specific ballistics tools. You should browse the a list of Matlab products at this link: Matlab Products

Ballstic Impact of Bullets on armor

I don't know af any specific ballistics tools. You should browse the a list of Matlab products at this link: Matlab Products

8 månader ago | 0

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Answered

How to find theta and theta dot in a simple pendulum simulation in MATLAB.

I'm not sure at all what your system equations are. The first rule of dynamics is where you have translational modes of motion ...

How to find theta and theta dot in a simple pendulum simulation in MATLAB.

I'm not sure at all what your system equations are. The first rule of dynamics is where you have translational modes of motion ...

8 månader ago | 0

Answered

What is a "system variable" in a Simulink model?

In this context, the "system" is the device that you are modelling. Therefore, a "system variable" is one of the variables in y...

What is a "system variable" in a Simulink model?

In this context, the "system" is the device that you are modelling. Therefore, a "system variable" is one of the variables in y...

8 månader ago | 1

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Answered

Undefined function 'simset' for input arguments of type 'char'.

simset is an obsolete function. See documentation here. It says to use the Configuration Parameters dialog box.

Undefined function 'simset' for input arguments of type 'char'.

simset is an obsolete function. See documentation here. It says to use the Configuration Parameters dialog box.

8 månader ago | 0

Answered

Newtons method for finding minimum of a function.

Here is another variation; function [f,g,h] = myfunction(x) f1 = @(z) exp(2*sin(z))-z; %function dx ...

Newtons method for finding minimum of a function.

Here is another variation; function [f,g,h] = myfunction(x) f1 = @(z) exp(2*sin(z))-z; %function dx ...

8 månader ago | 0

Answered

help me in trying to solve the secant method

Try preallocating x, right after you define n: n = 100; x = nan(1,n); ...

help me in trying to solve the secant method

Try preallocating x, right after you define n: n = 100; x = nan(1,n); ...

8 månader ago | 0

Answered

trying to calculate the central diff approximation

There is a Matlab function "diff" which will do this. Otherwise, your subscripts must all match (2:end-1) Adi_1 = diff(Vdi_1...

trying to calculate the central diff approximation

There is a Matlab function "diff" which will do this. Otherwise, your subscripts must all match (2:end-1) Adi_1 = diff(Vdi_1...

8 månader ago | 0

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Answered

Performing calculations (Newton's method) over values in loop

Yes, your loop is not quite right. Notice your placement of the three lines i=1; converge = false; po = p_init(1); These t...

Performing calculations (Newton's method) over values in loop

Yes, your loop is not quite right. Notice your placement of the three lines i=1; converge = false; po = p_init(1); These t...

8 månader ago | 0

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Answered

Draw a circle for arbitrary orientation on spherical surface

My approach is to define the circle around the X-axis, then rotate it into the desired position through a Yaw-Pitch rotation. ...

Draw a circle for arbitrary orientation on spherical surface

My approach is to define the circle around the X-axis, then rotate it into the desired position through a Yaw-Pitch rotation. ...

9 månader ago | 1

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Answered

the meaning of basic matlab words

an argument is a constant or variable that you provide to a function; e.g. sin(x) % here x is the argument to the function sin...

the meaning of basic matlab words

an argument is a constant or variable that you provide to a function; e.g. sin(x) % here x is the argument to the function sin...

9 månader ago | 0

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Answered

How to alter Comet Speed

I don't see a way to control the speed of the comet function. There is a discussion of controlling the speed of an animated lin...

How to alter Comet Speed

I don't see a way to control the speed of the comet function. There is a discussion of controlling the speed of an animated lin...

9 månader ago | 0

Answered

Incorrect Answer Calculated For Force Calculation

It is assumed that you want to find F3 and y such that the system is in equilibrium (this is not stated) (and I disagree with D...

Incorrect Answer Calculated For Force Calculation

It is assumed that you want to find F3 and y such that the system is in equilibrium (this is not stated) (and I disagree with D...

9 månader ago | 0

Answered

Transformation Matrix Between Two Cartesian Systems

This is a very generic question and there are many ways to answer. It depends on what information you have about the two coordi...

Transformation Matrix Between Two Cartesian Systems

This is a very generic question and there are many ways to answer. It depends on what information you have about the two coordi...

9 månader ago | 0

Answered

Why is ode45 changing the value of the state variable between calls to my dynamics function?

ode45 implements the Dormand-Prince method which is an embedded 4th / 5th order Runge-Kutta method. For every "step" in the sol...

Why is ode45 changing the value of the state variable between calls to my dynamics function?

ode45 implements the Dormand-Prince method which is an embedded 4th / 5th order Runge-Kutta method. For every "step" in the sol...

9 månader ago | 0

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Answered

Implement friction into a model, related to the velocity. (Missile Launch)

This question is familiar. look here.

Implement friction into a model, related to the velocity. (Missile Launch)

This question is familiar. look here.

9 månader ago | 0

Answered

How to make a marker circle bold?

plot(x, y, 'ro', 'linewidth',2);

How to make a marker circle bold?

plot(x, y, 'ro', 'linewidth',2);

9 månader ago | 0

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Answered

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.

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.

9 månader ago | 0