Creating a matrix after a for loop - for-loop

I want to store the 9 numbers created with the for loop in a matrix. So I get a matrix for Mean_Power_after with 9 number. Now I only get one number for the Mean_Power_after.
Hope that anybody can help me with this.
x = 1681;
y = 2221;
for i = x:60:y
Power_GE_after = Velo_watt(i:i+60);
Mean_Power_after = mean(Power_GE_after); //% mean power of every minute
end

You are reseting the Mean_Power_after to 1 value each time you run through the loop. Declare Mean_Power_after before the loop, like you declare x and y, and then instead of setting equal to one thing each time you run through the loop, set it equal to itself PLUS that one thing. Don't know which programming language you are using so I don't know how to format it for you.

Related

Is there a way to use range with Z3ints in z3py?

I'm relatively new to Z3 and experimenting with it in python. I've coded a program which returns the order in which different actions is performed, represented with a number. Z3 returns an integer representing the second the action starts.
Now I want to look at the model and see if there is an instance of time where nothing happens. To do this I made a list with only 0's and I want to change the index at the times where each action is being executed, to 1. For instance, if an action start at the 5th second and takes 8 seconds to be executed, the index 5 to 12 would be set to 1. Doing this with all the actions and then look for 0's in the list would hopefully give me the instances where nothing happens.
The problem is: I would like to write something like this for coding the problem
list_for_check = [0]*total_time
m = s.model()
for action in actions:
for index in range(m.evaluate(action.number) , m.evaluate(action.number) + action.time_it_takes):
list_for_check[index] = 1
But I get the error:
'IntNumRef' object cannot be interpreted as an integer
I've understood that Z3 isn't returning normal ints or bools in their models, but writing
if m.evaluate(action.boolean):
works, so I'm assuming the if is overwritten in a way, but this doesn't seem to be the case with range. So my question is: Is there a way to use range with Z3 ints? Or is there another way to do this?
The problem might also be that action.time_it_takes is an integer and adding a Z3int with a "normal" int doesn't work. (Done in the second part of the range).
I've also tried using int(m.evaluate(action.number)), but it doesn't work.
Thanks in advance :)
When you call evaluate it returns an IntNumRef, which is an internal z3 representation of an integer number inside z3. You need to call as_long() method of it to convert it to a Python number. Here's an example:
from z3 import *
s = Solver()
a = Int('a')
s.add(a > 4);
s.add(a < 7);
if s.check() == sat:
m = s.model()
print("a is %s" % m.evaluate(a))
print("Iterating from a to a+5:")
av = m.evaluate(a).as_long()
for index in range(av, av + 5):
print(index)
When I run this, I get:
a is 5
Iterating from a to a+5:
5
6
7
8
9
which is exactly what you're trying to achieve.
The method as_long() is defined here. Note that there are similar conversion functions from bit-vectors and rationals as well. You can search the z3py api using the interface at: https://z3prover.github.io/api/html/namespacez3py.html

Input to different attributes values from a random.sample list

so this is what I'm trying to do, and I'm not sure how cause I'm new to python. I've searched for a few options and I'm not sure why this doesn't work.
So I have 6 different nodes, in maya, called aiSwitch. I need to generate random different numbers from 0 to 6 and input that value in the aiSiwtch*.index.
In short the result should be
aiSwitch1.index = (random number from 0 to 5)
aiSwitch2.index = (another random number from 0 to 5 different than the one before)
And so on unil aiSwitch6.index
I tried the following:
import maya.cmds as mc
import random
allswtich = mc.ls('aiSwitch*')
for i in allswitch:
print i
S = range(0,6)
print S
shuffle = random.sample(S, len(S))
print shuffle
for w in shuffle:
print w
mc.setAttr(i + '.index', w)
This is the result I get from the prints:
aiSwitch1 <-- from print i
[0,1,2,3,4,5] <--- from print S
[2,3,5,4,0,1] <--- from print Shuffle (random.sample results)
2
3
5
4
0
1 <--- from print w, every separated item in the random.sample list.
Now, this happens for every aiSwitch, cause it's in a loop of course. And the random numbers are always a different list cause it happens every time the loop runs.
So where is the problem then?
aiSwitch1.index = 1
And all the other aiSwitch*.index always take only the last item in the list but the time I get to do the setAttr. It seems to be that w is retaining the last value of the for loop. I don't quite understand how to
Get a random value from 0 to 5
Input that value in aiSwitch1.index
Get another random value from 0 to 6 different to the one before
Input that value in aiSwitch2.index
Repeat until aiSwitch5.index.
I did get it to work with the following form:
allSwitch = mc.ls('aiSwitch')
for i in allSwitch:
mc.setAttr(i + '.index', random.uniform(0,5))
This gave a random number from 0 to 5 to all aiSwitch*.index, but some of them repeat. I think this works cause the value is being generated every time the loop runs, hence setting the attribute with a random number. But the numbers repeat and I was trying to avoid that. I also tried a shuffle but failed to get any values from it.
My main mistake seems to be that I'm generating a list and sampling it, but I'm failing to assign every different item from that list to different aiSwitch*.index nodes. And I'm running out of ideas for this.
Any clues would be greatly appreciated.
Thanks.
Jonathan.
Here is a somewhat Pythonic way: shuffle the list of indices, then iterate over it using zip (which is useful for iterating over structures in parallel, which is what you need to do here):
import random
index = list(range(6))
random.shuffle(index)
allSwitch = mc.ls('aiSwitch*')
for i,j in zip(allSwitch,index):
mc.setAttr(i + '.index', j)

Generating Random Numbers and Letters

Keep getting this error sometimes when mid is ZERO:
Invalid procedure call or argument: 'Mid'
How would I fix this?
Function CreateRandomString(iSize)
Const VALID_TEXT = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
Dim sNewSearchTag
Dim I
For I = 0 To iSize
Randomize
sNewSearchTag = sNewSearchTag & Mid(VALID_TEXT,Round(Rnd * Len(VALID_TEXT)),1)
Next
CreateRandomString = sNewSearchTag
End Function
For the random range to be correct you need to make sure the random value generated is between 1 and the length of the VALID_TEXT string value.
The simple formula to do this using Rnd() is
(Rnd() * Len(VALID_TEXT)) + 1
also move Randomize() outside the loop, as it is you'll just make it less random as you're resetting the seed with every iteration of the loop.
The reason for the error is Mid() expects a valid start and size, which a zero value is not. See this question for more information.
More information about random number ranges can be found in this answer to another question.
The second argument of Mid is 1 based. That means that if you did:
Mid(VALID_TEXT,1,1)
you will get "a", not "b" as you might be expecting.
An easy fix would be to add 1 to the second argument, but then you'll run into the same problem on the top end. Typically people will round a random number down after multiplying it instead of using Math.Round, either view Math.Floor or Integer truncation.

Assignment problems with simple random number generation in Modelica

I am relatively new to Modelica (Dymola-environment) and I am getting very desperate/upset that I cannot solve such a simple problem as a random number generation in Modelica and I hope that you can help me out.
The simple function random produces a random number between 0 and 1 with an input seed seedIn[3] and produces the output seed seedOut[3] for the next time step or event. The call
(z,seedOut) = random(seedIn);
works perfectly fine.
The problem is that I cannot find a way in Modelica to compute this assignment over time by using the seedOut[3] as the next seedIn[3], which is very frustrating.
My simple program looks like this:
*model Randomgenerator
Real z;
Integer seedIn[3]( start={1,23,131},fixed=true), seedOut[3];
equation
(z,seedOut) = random(seedIn);
algorithm
seedIn := seedOut;
end Randomgenerator;*
I have tried nearly all possibilities with algorithm assignments, initial conditions and equations but none of them works. I just simply want to use seedOut in the next time step. One problem seems to be that when entering into the algorithm section, neither the initial conditions nor the values from the equation section are used.
Using the 'sample' and 'reinit' functions the code below will calculate a new random number at the frequency specified in 'sample'. Note the way of defining the "start value" of seedIn.
model Randomgenerator
Real seedIn[3] = {1,23,131};
Real z;
Real[3] seedOut;
equation
(z,seedOut) = random(seedIn);
when sample(1,1) then
reinit(seedIn,pre(seedOut));
end when;
end Randomgenerator;
The 'pre' function allows the use of the previous value of the variable. If this was not used, the output 'z' would have returned a constant value. Two things regarding the 'reinint' function, it requires use of 'when' and requires 'Real' variables/expressions hence seedIn and seedOut are now defined as 'Real'.
The simple "random" generator I used was:
function random
input Real[3] seedIn;
output Real z;
output Real[3] seedOut;
algorithm
seedOut[1] :=seedIn[1] + 1;
seedOut[2] :=seedIn[2] + 5;
seedOut[3] :=seedIn[3] + 10;
z :=(0.1*seedIn[1] + 0.2*seedIn[2] + 0.3*seedIn[3])/(0.5*sum(seedIn));
end random;
Surely there are other ways depending on the application to perform this operation. At least this will give you something to start with. Hope it helps.

Matlab subscript error

I am writing a simple code in matlab which has the purpose of creating the histogram of a grayscale image without using the function hist. I am stuck at the point in which mathlab displays the error "Subscript indices must either be real positive integers or logicals." Can you help me finding where is the wrong indices?
indirizzo='file.jpg';
immagine=imread(indirizzo);
immaginebn=rgb2gray(immagine);
n=zerps(0,255);
for x=0:255;
numeroennesimo=sum(sum(immaginebn==x));
n(x)=numeroennesimo;
end
plot(x,n)
you cant use 0 as index. Either make n(x+1) or for x = 1:256 and substract the 1 in your comparison. And there is a typo, I guess it means zeros instead of zerps, which also doesnt work with a 0. And one more, your plot will also not work as the x has only a size of 1 while n is an array of 266 and for a histogram I would use a barplot instead.
indirizzo='file.jpg';
immagine=imread(indirizzo);
immaginebn=rgb2gray(immagine);
n=zeros(1,256);
for x=0:255;
numeroennesimo=sum(sum(immaginebn==x-1));
n(x+1)=numeroennesimo;
end
bar(0:255,n)
or
indirizzo='file.jpg';
immagine=imread(indirizzo);
immaginebn=rgb2gray(immagine);
n=zeros(1,256);
xplot=zeros(1,256);
for x=1:256;
numeroennesimo=sum(sum(immaginebn==x-1));
n(x)=numeroennesimo;
xplot(x) = x-1;
end
plot(xplot,n)

Resources