I am making a pyomo model, where i want to use random numbers for my two dimensional parameters. I put a small python script for random numbers that looks exactly what i wanted to see for my two dimensional parameter. I am getting a TypeError: Cannot convert object of type 'list'(value =[[....]] to a numeric value. in my objective function. Below is my objective function and random numbers script.
model.obj = Objective(expr=sum(model.C[v,l] * model.T[v,l] for v in model.V for l in model.L) + \
sum(model.OC[o,l] * model.D[o,l] for o in model.O for l in model.L), sense=minimize)
import random
C = [[] for i in range(7)]
for i in range(7):
for j in range(5):
C[i]+= [random.randint(100,500)]
model.C = Param(model.V, model.L, initialize=C)
Please let me know if someone can help fixing this.
You should initialize your parameter using a function instead of a nested list
def init_c(m, i, j):
return random.randint(100,500)
model.c = Param(model.V, model.L, initialize=init_c)
Related
Problems Detail:
My routine is a simple set of equations, the result must yield the result as an array of float elements with a precission of 4 decimals. The problem is that the .round(4) method is not working.
What I tried:
Used .round(4)
Used .to_f(4)
My code is as follows:
`
def bar_triang(p1,p2,p3)
#your code here
bary=[]
x0= [p1[0],p2[0],p3[0]].sum
x0t= x0.div(3)
x0tf = x0t.round(4)
bary=bary.push(x0tf)
y0 = [p1[1],p2[1],p3[1]].sum
y0t =y0.div(3)
y0tf = y0t.round(4)
bary=bary.push(y0tf)
p bary
end
`
Note: The routine accepts an array of the following shape [p1,p2,p3] in which p1 to p3 are coordinates [x,y]. [p1,p2,p3] is an array of arrays.
What I am expecting?
An array of two float elements with 4 decimals of precission.
What I am getting?
An array of two float elements with no decimals precission.
What I want to know?
Why the .round(4) method does not work in the context of my code?
How can I use .round(4) within the context of my code in order to make it work properly?
Your problem is not because the round(4) not working correctly. It's because part of code:
x0t = x0.div(3) # Always return Integer
x0tf = x0t.round(4)
I suggest using / instead of div:
x0t = x0 / 3 # return Float
x0tf = x0t.round(4)
The final code will print the distance between states. I'm trying to print the menu with the names of the states numbered and vertically. I really struggle to find my mistakes.
This code doesn't raise any error, it just prints nothing, empty.
state_data = """
LA 34.0522°N 118.2437°W
Florida 27.6648°N 81.5158°W
NY 40.7128°N 74.0060°W"""
states = []
import re
state_data1 = re.sub("[°N#°E]", "", state_data)
def process_states(string):
states_temp = string.split()
states = [(states_temp[x], float(states_temp[x + 1]), float(states_temp[x + 2])) for x in
range(0, len(states_temp), 3)]
return states
def menu():
for state_data in range(state_data1):
print(f'{state_data + 1} {name[number]}')
My first guess is, your code does not print anything without errors because you never actually execute process_airports() nor menu().
You have to call them like this at the end of your script:
something = process_airports(airport_data1)
menu()
This will now raise some errors though. So let's address them.
The menu() function will raise an error because neither name nor number are defined and because you are trying to apply the range function over a string (airport_data1) instead of an integer.
First fixing the range error: you mixed two ideas in your for-loop: iterating over the elements in your list airport_data1 and iterating over the indexes of the elements in the list.
You have to choose one (we'll see later that you can do both at once), in this example, I choose to iterate over the indexes of the list.
Then, since neither name nor number exists anywhere they will raise an error. You always need to declare variables somewhere, however, in this case they are not needed at all so let's just remove them:
def menu(data):
for i in range(len(data)):
print(f'{i + 1} {data[i]}')
processed_airports = process_airports(airport_data1)
menu(processed_airports)
Considering data is the output of process_airports()
Now for some general advices and improvements.
First, global variables.
Notice how you can access airport_data1 within the menu() function just fine, while it works this is not something recommended, it's usually better to explicitly pass variables as arguments.
Notice how in the function I proposed above, every single variable is declared in the function itself, there is no information coming from a higher scope. Again, this is not mandatory but makes the code way easier to work with and understand.
airport_data = """
Alexandroupoli 40.855869°N 25.956264°E
Athens 37.936389°N 23.947222°E
Chania 35.531667°N 24.149722°E
Chios 38.343056°N 26.140556°E
Corfu 39.601944°N 19.911667°E"""
airports = []
import re
airport_data1 = re.sub("[°N#°E]", "", airport_data)
def process_airports(string):
airports_temp = string.split()
airports = [(airports_temp[x], float(airports_temp[x + 1]), float(airports_temp[x + 2])) for x in
range(0, len(airports_temp), 3)]
return airports
def menu(data):
for i in range(len(data)):
print(f'{i + 1} {data[i]}')
# I'm adding the call to the functions for clarity
data = process_airports(airport_data1)
menu(data)
The printed menu now looks like that:
1 ('Alexandroupoli', 40.855869, 25.956264)
2 ('Athens', 37.936389, 23.947222)
3 ('Chania', 35.531667, 24.149722)
4 ('Chios', 38.343056, 26.140556)
5 ('Corfu', 39.601944, 19.911667)
Second and this is mostly fyi, but you can access both the index of a iterable and the element itself by looping over enumerate() meaning, the following function will print the exact same thing as the one with range(len(data)). This is handy if you need to work with both the element itself and it's index.
def menu(data):
for the_index, the_element in enumerate(data):
print(f'{the_index + 1} {the_element}')
Suppose if I have the following in Julia:
mutable struct emptys
begin_time::Dict{Float64,Float64}; finish_time::Dict{Float64,Float64}; Revenue::Float64
end
population = [emptys(Dict(),Dict(),-Inf) for i in 1:n_pop] #n_pop is a large positive integer value.
for ind in 1:n_pop
r = rand()
append!(population[ind].Revenue, r)
append!(population[ind].begin_time, Dict(r=>cld(r^2,rand())))
append!(population[ind].finish_time, Dict(r=>r^3/rand()))
end
Now I want to sort this population based on the Revenue value. Is there any way for Julia to achieve this? If I were to do it in Python it would be something like this:
sorted(population, key = lambda x: x.Revenue) # The population in Python can be prepared using https://pypi.org/project/ypstruct/ library.
Please help.
There is a whole range of sorting functions in Julia. The key functions are sort (corresponding to Python's sorted) and sort! (corresponding to Python's list.sort).
And as in Python, they have a couple of keyword arguments, one of which is by, corresponding to key.
Hence the translation of
sorted(population, key = lambda x: x.Revenue)
would be
getrevenue(e::emptys) = e.Revenue
sort(population, by=getrevenue)
Or e -> e.Revenue, but having a getter function is good style anyway.
Here is my problem.
I'm using sympy and a complex matrix P (all elements of P are complex valued).
I wanna extract the real/imaginary part of the first row.
So, I use the following sequence:
import sympy as sp
P = sp.Matrix([ [a+sp.I*b,c-sp.I*d], [c-sp.I*d,a+sp.I*b] ])
Row = P.row(0)
Row.as_mutable()
Re_row = sp.re(Row)
Im_row = sp.im(Row)
But the code returns me the following error:
"AttributeError: ImmutableMatrix has no attribute as_coefficient."
The error occurs during the operation sp.re(Row) and sp.im(Row)...
Sympy tells me that Row is an Immutable matrix but I specify that I want a mutable one...
So I'm in a dead end, and I don't have the solution...
Could someone plz help me ?
thank you very much !
Most SymPy functions won't work if you just pass a Matrix to them directly. You need to use the methods of the Matrix, or if there is not such method (as is the case here), use applyfunc
In [34]: Row.applyfunc(re)
Out[34]: [re(a) - im(b) re(c) + im(d)]
In [35]: Row.applyfunc(im)
Out[35]: [re(b) + im(a) -re(d) + im(c)]
(I've defined a, b, c, and d as just ordinary symbols here, if you set them as real the answer will come out much simpler).
I am trying to run a granger causality test on two currency pairs but I seem to get this error message in Shell whenever I try and test it. Can anyone please advise?
I am very new to programming and need this to run an analysis for my project. In shell, I am putting -
import ats15
ats15.grangertest('EURUSD', 'EURGBP', 8)
What is going wrong? I have copied the script below.
Thanks in advance.
Heading ##def grangertest(Y,X,maxlag):
"""
Performs a Granger causality test on variables (vectors) Y and X.
The null hypothese is: Does X cause Y ?
Returned value: pvalue, F, df1, df2
"""
# Create linear model involving Y lags only.
n = len(Y)
if n != len(X):
raise ValueError, "grangertest: incompatible Y,X vectors"
M = [ [0] * maxlag for i in range(n-maxlag)]
for i in range(maxlag, n):
for j in range(1, maxlag+1):
M[i-maxlag][j-1] = Y[i-j]
fit = ols(M, Y[maxlag:])
RSSr = fit.RSS
# Create linear model including X lags.
for i in range(maxlag, n):
xlagged = [X[i-j] for j in range(1, maxlag+1)]
M[i-maxlag].extend(xlagged)
fit = ols(M, Y[maxlag:])
RSSu = fit.RSS
df1 = maxlag
df2 = n - 2 * maxlag - 1
F = ((RSSr - RSSu)/df1)/(RSSu/df2)
pvalue = 1.0 - stats.f.cdf(F,df1,df2)
return pvalue, F, df1, df2, RSSr, RSSu
You didn't post the full traceback, but this error message:
TypeError: unsupported operand type(s) for -: 'str' and 'int'
means what it says. There's an operand - -- the subtraction operator -- and it doesn't know how to handle subtracting an integer from a string. Why would strings be involved? Well, you're calling the function with:
ats15.grangertest('EURUSD', 'EURGBP', 8)
and so you're giving grangertest two strings and an integer. But it seems like grangertest expects
def grangertest(Y,X,maxlag):
two sequences (lists, arrays, whatever) of numbers to use as Y and X, not strings. If EURUSD and EURGBP are names you've given to lists beforehand, then you don't need the quotes:
ats15.grangertest(EURUSD, EURGBP, 8)
but if not, then you should pass grangertest the lists under whatever name you've called them.
The input to the grangertest function must be two lists of numbers. grangertest doesn't know anything about currencies, so passing it currency strings won't work.
You have to fetch the exchange rate data somehow so that you can pass it to grangertest. If EURUSD and EURGBP are variables, then you don't put quotes around them when you pass them to a function (e.g. ats15.grangertest(EURUSD, EURGBP, 8)).