Develop Reference

cant get raycast to work from angles 90 to 270 pygame

Im working on a ray-caster as a project in pygame and i've stumbled upon an issue where the ray casts in the opposite direction from angles 90 to 270. Ive tried making the DDA algorithm subtract the x and y values instead of add them but it does nothing. The ray-cast code starts at line 73, here is the code:
import pygame
import sys
import math
# initialise pygame, set display and clock
WIDTH = 600
HEIGHT = 600
pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
clock = pygame.time.Clock()
#map
world = [
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1],
[1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1],
[1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1],
[1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1],
[1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1],
[1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1],
[1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
]
TILE = WIDTH/len(world)
tile_list = []
for row_num, row in enumerate(world):
for col_num, col in enumerate(row):
if col == 1:
x, y = col_num * TILE, row_num * TILE
rect = pygame.Rect(x, y, TILE, TILE)
tile_list.append(rect)
planeX = 0
planeY = 0.66
dirX = -1
dirY = 0
player_rect = pygame.Rect(60, 60, 30, 30)
vel = 0.5
fps = 60
#sets the origin for all vectors
startpoint = pygame.math.Vector2(player_rect[0] + player_rect[2]/2, player_rect[1] + player_rect[3]/2)
#sets the differnt endpoints for all vectors
endpoint = pygame.math.Vector2(15,0)
fov = 60
angle = 0
angle_rest = angle - fov//2
radian = 0.01745329
lineStartPoint = startpoint
lineEndPoint = endpoint
turnRate = 5
#DDA algorithm/raycasting
def castRay(rayAngle):
slope = math.tan(radian * rayAngle)
COLLIDE = False
x = startpoint[0]
y = startpoint[1]
#loop that adds 1 to x and the slope to y until it collides with a wall
while not COLLIDE and x < WIDTH and x > 0:
x += 1
y += slope
point = pygame.Rect(x,y, 1,1)
for tile in tile_list:
rect = pygame.Rect(tile)
if(point.colliderect(rect)):
COLLIDE = True
#draws line for this loop
pygame.draw.line(screen, (255,0,0), startpoint, (x, y))
x = startpoint[0]
y = startpoint[1]
#loop that adds 1/slope to x and 1 to y until it collides with a wall
while not COLLIDE and y < HEIGHT and y > 0:
x += 1/slope
y += 1
point = pygame.Rect(x,y, 1,1)
for tile in tile_list:
rect = pygame.Rect(tile)
if(point.colliderect(rect)):
COLLIDE = True
pygame.draw.line(screen, (0,0,255), startpoint, (x, y))
while True:
clock.tick(fps)
screen.fill((135, 53, 53))
# get pressed keys
keys = pygame.key.get_pressed()
# delta x and delta y values
dx, dy = 0, 0
startpoint = pygame.math.Vector2(player_rect[0] + player_rect[2]/2, player_rect[1] + player_rect[3]/2)
current_endpoint = startpoint + endpoint.rotate(angle)
lineStartPoint = current_endpoint + endpoint.rotate((angle+90) % 360)
lineEndPoint = current_endpoint - endpoint.rotate((angle+90) % 360)
angle_rest = (angle - fov//2) % 360
#movement
if keys[pygame.K_UP]:
dx -= (startpoint[0] - current_endpoint[0])*vel
dy -= (startpoint[1] - current_endpoint[1])*vel
if keys[pygame.K_DOWN]:
dx += (startpoint[0] - current_endpoint[0])*vel
dy += (startpoint[1] - current_endpoint[1])*vel
if keys[pygame.K_RIGHT]:
angle = (angle+turnRate) % 360
if keys[pygame.K_LEFT]:
angle = (angle-turnRate) % 360
# this is where collision detection starts
x_projection = player_rect.move(dx, 0)
y_projection = player_rect.move(0, dy)
for tile in tile_list:
pygame.draw.rect(screen, (99, 99, 99), tile)
if x_projection.colliderect(tile):
if dx > 0:
dx = tile.left - player_rect.right
elif dx < 0:
dx = tile.right - player_rect.left
elif y_projection.colliderect(tile):
if dy > 0:
dy = tile.top - player_rect.bottom
elif dy < 0:
dy = tile.bottom - player_rect.top
player_rect.move_ip(dx, dy)
pygame.draw.rect(screen, (38, 136, 126), player_rect)
pygame.draw.line(screen , (255,0,0), startpoint, current_endpoint)
pygame.draw.line(screen, 255, (lineStartPoint), (lineEndPoint))
castRay(angle)
print(angle)
# remember to update the display
pygame.display.update()
for event in pygame.event.get():
if event.type == pygame.QUIT:
exit()

If the angle is between 90° and 270°, you must reverse the direction:
def castRay(rayAngle):
slope = math.tan(math.radians(rayAngle))
dx = 1
if rayAngle > 90 and rayAngle < 270:
slope *= -1
dx *= -1
COLLIDE = False
x = startpoint[0]
y = startpoint[1]
#loop that adds 1 to x and the slope to y until it collides with a wall
while not COLLIDE and x < WIDTH and x > 0:
x += dx
y += slope
point = pygame.Rect(x,y, 1,1)
for tile in tile_list:
rect = pygame.Rect(tile)
if(point.colliderect(rect)):
COLLIDE = True
However, I suggest to simplify your code. Compute the direction vector:
dx, dy = math.cos(angleRad), math.sin(angleRad)
The components of the direction vector by the reciprocal maximum component so that the larger component becomes 1:
s = max(abs(dx), abs(dy))
dx /= s
dy /= s
function castRay:
def castRay(rayAngle):
angleRad = math.radians(rayAngle)
dx, dy = math.cos(angleRad), math.sin(angleRad)
s = max(abs(dx), abs(dy))
dx /= s
dy /= s
COLLIDE = False
x, y = startpoint
while not COLLIDE and 0 <= y < WIDTH and 0 < y < HEIGHT:
x += dx
y += dy
point = pygame.Rect(x,y, 1,1)
for tile in tile_list:
rect = pygame.Rect(tile)
if(point.colliderect(rect)):
COLLIDE = True
pygame.draw.line(screen, (255,0,0), startpoint, (x, y))

Image rotation and translation using an aruco marker

I am trying to warp an image based of the orientation of the camera relative to an aruco marker in the middle of the image. I have managed to get the translation part working but the rotation element is not working. It seems like the image isn't rotating about the centre of the aruco axis. The reference image was taken straight on and the warped image is overlayed.
# Find centre of the marker
top_left_x = (corners[0][0][0, 0])
top_left_y = (corners[0][0][0, 1])
top_right_x = (corners[0][0][1, 0])
top_right_y = (corners[0][0][1, 1])
bottom_right_x = (corners[0][0][2, 0])
bottom_right_y = (corners[0][0][2, 1])
bottom_left_x = (corners[0][0][3, 0])
bottom_left_y = (corners[0][0][3, 1])
# Compare this to the centre of the image to calculate the offset
mid_x = top_right_x - (top_right_x - top_left_x) / 2
mid_y = bottom_left_y - (bottom_left_y - top_left_y) / 2
x_centre = 960
y_centre = 540
x_offset = x_centre - mid_x
y_offset = y_centre - mid_y
if x_centre > mid_x: # gone right
x_offset = 1 * (x_centre - mid_x) # correction to the left
if x_centre < mid_x: # gone left
x_offset = -1 * (mid_x - x_centre) # correction to the right
if y_centre > mid_y: # gone down
y_offset = 1 * (y_centre - mid_y) # correction to the left
if y_centre < mid_y: # gone left
y_offset = -1 * (mid_y - y_centre) # correction to the right
current_z_distance = (math.sqrt((pos_camera[0]**2) + (pos_camera[1]**2) +
(pos_camera[2]**2))) * 15.4
img = cv2.imread('Corrected.png')
corrected_z = 31 # Distance when image was taken
initial_z_distance = corrected_z * 15.4 # Pixels
delta_z = (initial_z_distance - current_z_distance)
scale_factor = current_z_distance / initial_z_distance # how much larger the image
now is. Used for scaling
z_translation = delta_z * 1.54 # how much the image has moved. negative for going
backwards
z_translation = 0
z_axis = 960 / scale_factor
proj2dto3d = np.array([[1, 0, -mid_x],
[0, 1, -mid_y],
[0, 0, 0],
[0, 0, 1]], np.float32)
proj3dto2d = np.array([[z_axis, 0, mid_x, 0],
[0, z_axis, mid_y, 0], # defines to centre of rotation
[0, 0, 1, 0]], np.float32)
trans = np.array([[1, 0, 0, x_offset * -1], # Working
[0, 1, 0, y_offset * -1],
[0, 0, 1, 960], # keep as 960
[0, 0, 0, 1]], np.float32)
x = math.degrees(roll_marker) * -1 # forwards and backwards
y = math.degrees(pitch_marker) * -1 # Left and right
z = 0
rx = np.array([[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]], np.float32) #
ry = np.array([[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]], np.float32)
rz = np.array([[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]], np.float32)
ax = float(x * (math.pi / 180.0)) # 0
ay = float(y * (math.pi / 180.0))
az = float(z * (math.pi / 180.0)) # 0
rx[1, 1] = math.cos(ax) # 0
rx[1, 2] = -math.sin(ax) # 0
rx[2, 1] = math.sin(ax) # 0
rx[2, 2] = math.cos(ax) # 0
ry[0, 0] = math.cos(ay)
ry[0, 2] = -math.sin(ay)
ry[2, 0] = math.sin(ay)
ry[2, 2] = math.cos(ay)
rz[0, 0] = math.cos(az) # 0
rz[0, 1] = -math.sin(az) # 0
rz[1, 0] = math.sin(az) # 0
rz[1, 1] = math.cos(az) # 0
# Translation matrix
# r = rx.dot(ry) # if we remove the lines we put r=ry
r = rx.dot(ry) # order may need to be changed
final = proj3dto2d.dot(trans.dot(r.dot(proj2dto3d))) # just rotation
dst = cv2.warpPerspective(img, final, (img.shape[1], img.shape[0]), None, cv2.INTER_LINEAR, cv2.BORDER_CONSTANT, (255, 255, 255))

Pygame won't draw quads in the right order

I have been trying to make a 3d engine with python for some time, and I have gotten pretty far, however I have found a problem in when I try and sort items in a list, the sorting flips when you are close enough to the cube.
main.py:
import os
os.environ["SDL_VIDEO_CENTERED"] = '1'
os.environ["PYGAME_HIDE_SUPPORT_PROMPT"] = '1'
import pygame
from pygame import gfxdraw
import math
from matrix import matrix_multiplication
import mesh
from random import randint as random
import time
startTime = time.time()
black, white, blue = (20, 20, 20), (230, 230, 230), (0, 154, 255)
width, height = 700, 700
pygame.init()
pygame.display.set_caption("3D Engine")
screen = pygame.display.set_mode((width, height))
clock = pygame.time.Clock()
frames = 60
outline = False
rs, gs, bs = [random(0, 255) for i in range(len(mesh.faces))], [random(0, 255) for i in
range(len(mesh.faces))], [random(0, 255) for i in range(len(mesh.faces))]
angle_x = 0
angle_y = 0
angle_z = 0
pos_x = 0
pos_y = 0
pos_z = 0
cube_position = [width//2, height//2]
scale = 600
speed = 0.001
points = [[[i] for i in j] for j in mesh.verts]
movSpeed = 0.001
font = pygame.font.SysFont("Corbel", 23)
def avarageX(i):
return (new_points[mesh.faces[i][0]][0][0] + new_points[mesh.faces[i][1]][0][0] + new_points[mesh.faces[i][2]][0][0] + new_points[mesh.faces[i][3]][0][0]) / 4
def avarageY(i):
return (new_points[mesh.faces[i][0]][1][0] + new_points[mesh.faces[i][1]][1][0] + new_points[mesh.faces[i][2]][1][0] + new_points[mesh.faces[i][3]][1][0]) / 4
def avarageZ(i):
return (new_points[mesh.faces[i][0]][2][0] + new_points[mesh.faces[i][1]][2][0] + new_points[mesh.faces[i][2]][2][0] + new_points[mesh.faces[i][3]][2][0]) / 4
def distToCam(i):
a = [0, 0, 0]
b = [avarageX(i), avarageY(i), avarageZ(i)]
return math.dist(a, b)
print("It took: {} seconds".format(time.time() - startTime))
run = True
while run:
dt = clock.tick(frames)
fps = clock.get_fps()
screen.fill(white)
keys = pygame.key.get_pressed()
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
index = 0
projected_points = [j for j in range(len(points))]
rotation_x = [[1, 0, 0],
[0, math.cos(angle_x), -math.sin(angle_x)],
[0, math.sin(angle_x), math.cos(angle_x)]]
rotation_y = [[math.cos(angle_y), 0, -math.sin(angle_y)],
[0, 1, 0],
[math.sin(angle_y), 0, math.cos(angle_y)]]
rotation_z = [[math.cos(angle_z), -math.sin(angle_z), 0],
[math.sin(angle_z), math.cos(angle_z), 0],
[0, 0, 1]]
new_points = []
for point in points:
rotated_2d = matrix_multiplication(rotation_y, point)
rotated_2d = matrix_multiplication(rotation_x, rotated_2d)
rotated_2d = matrix_multiplication(rotation_z, rotated_2d)
new_point = [[rotated_2d[0][0] + pos_x], [rotated_2d[1][0] + pos_y], [rotated_2d[2][0] - pos_z]]
new_points.append(new_point)
distance = 5
z = 1 / (distance - new_point[2][0])
projection_matrix = [[z, 0, 0],
[0, z, 0]]
projected_2d = matrix_multiplication(projection_matrix, new_point)
x = int(projected_2d[0][0] * scale) + cube_position[0]
y = int(projected_2d[1][0] * scale) + cube_position[1]
projected_points[index] = [x, y]
index += 1
zs = [[distToCam(i), i] for i in range(len(mesh.faces))]
zs.sort(reverse=True)
faces = [[mesh.faces[zs[i][1]], zs[i][1]] for i in range(len(mesh.faces))]
fi = 0
for f in faces:
gfxdraw.filled_polygon(screen, [projected_points[f[0][0]], projected_points[f[0][1]], projected_points[f[0][2]], projected_points[f[0][3]]], (rs[zs[fi][1]], gs[zs[fi][1]], bs[zs[fi][1]]))
gfxdraw.aapolygon(screen, [projected_points[f[0][0]], projected_points[f[0][1]], projected_points[f[0][2]], projected_points[f[0][3]]], (rs[zs[fi][1]], gs[zs[fi][1]], bs[zs[fi][1]]))
fi += 1
angle_x += (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * speed * dt
angle_y += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * speed * dt
pos_x += (keys[pygame.K_d] - keys[pygame.K_a]) * movSpeed * dt
pos_z += (keys[pygame.K_w] - keys[pygame.K_s]) * movSpeed * dt
text = font.render(str(round(fps, 1)), False, black)
screen.blit(text, (0, 0))
pygame.display.update()
pygame.quit()
The matrix multiplication
matrix.py:
def matrix_multiplication(a, b):
columns_a = len(a[0])
rows_a = len(a)
columns_b = len(b[0])
rows_b = len(b)
result_matrix = [[j for j in range(columns_b)] for i in range(rows_a)]
if columns_a == rows_b:
for x in range(rows_a):
for y in range(columns_b):
sum = 0
for k in range(columns_a):
sum += a[x][k] * b[k][y]
result_matrix[x][y] = sum
return result_matrix
else:
print("columns of the first matrix must be equal to the rows of the second matrix")
return None
The mesh data.
mesh.py:
verts = [
[1, 1, 1],
[1, 1, -1],
[1, -1, 1],
[1, -1, -1],
[-1, 1, 1],
[-1, 1, -1],
[-1, -1, 1],
[-1, -1, -1]
]
faces = [
[0, 4, 6, 2],
[3, 2, 6, 7],
[7, 6, 4, 5],
[5, 1, 3, 7],
[1, 0, 2, 3],
[5, 4, 0, 1]
]
WARNING: There might be flashing lights on startup

You have to compute the distance of the camera position ([0, 0, distance]) to the points in world space (new_points), instead of the points in model space (points):
def distToCam(i):
a = [0, 0, distance]
b = [sum(new_points[mesh.faces[i][pi]][j][0] for pi in range(4)) / 4 for j in range(3)]
return math.dist(a, b)

simple version of Game Of Life game doesnt behave correctly [duplicate]

This question already has answers here:
Does Python make a copy of objects on assignment?
(5 answers)
Closed 2 years ago.
Here's the full code. I've left out few unnecessary things
import random
import pygame
FPS = 1
WIDTH, HEIGHT = 400, 400
RESOLUTION = 40
GRAY = (200, 200, 200)
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
WIN = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Game of Life")
def draw_grid(win, cols, rows):
for i in range(cols):
for j in range(rows):
x = i * RESOLUTION
y = j * RESOLUTION
pygame.draw.rect(win, GRAY, (x, y, RESOLUTION, RESOLUTION), 1)
def make_2d_array(cols, rows):
arr = []
for i in range(cols):
arr.append([])
for j in range(rows):
arr[i].append(0)
return arr
def count_neighbours(grid, x, y):
neighbourCount = 0
for i in range(-1, 2):
for j in range(-1, 2):
neighbourCount += grid[x + i][y + j]
return neighbourCount
def draw_squares(win, grid, cols, rows):
#nextA = make_2d_array(cols, rows)
nextA = grid
for i in range(len(grid)):
for j in range(len(grid[i])):
x = i * RESOLUTION
y = j * RESOLUTION
if grid[i][j] == 1:
pygame.draw.rect(win, WHITE, (x, y, RESOLUTION, RESOLUTION))
elif grid[i][j] == 0:
pygame.draw.rect(win, BLACK, (x, y, RESOLUTION, RESOLUTION))
for i in range(cols):
for j in range(rows):
if i == 0 or i == cols-1 or j == 0 or j == rows-1:
nextA[i][j] = grid[i][j]
else:
state = grid[i][j]
neighbours = count_neighbours(grid, i, j)
if state == 0 and neighbours == 3:
nextA[i][j] = 1
elif state == 1 and (neighbours < 2 or neighbours > 3):
nextA[i][j] = 0
else:
nextA[i][j] = state
grid = nextA
def main():
run = True
clock = pygame.time.Clock()
cols = int(WIDTH / RESOLUTION)
rows = int(HEIGHT / RESOLUTION)
grid = make_2d_array(cols, rows)
"""for i in range(cols):
for j in range(rows):
grid[i][j] = random.randint(0, 1)"""
#glider test
grid = [[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 1, 0, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 1, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0]]
while run:
clock.tick(FPS)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
draw_squares(WIN, grid, cols, rows)
draw_grid(WIN, cols, rows)
pygame.display.update()
pygame.quit()
main()
I was following along with a tutorial that was written in Java or JavaScript but the rules are the same and should work but they don't.
The rules simplified should be this:
if state == 0 and neighbours == 3:
nextA[i][j] = 1
elif state == 1 and (neighbours < 2 or neighbours > 3):
nextA[i][j] = 0
else:
nextA[i][j] = state
but when I run the code the first if-statement works I'm pretty sure (it's kinda hard to understand the program behaves weirdly).

The implementation of the rules is correct, but in Conway's Game of Life you have to create a new and empty grid every turn. The fields in the new grid must be determined depending on the fields in the current grid and the evolution rules.
Create a new and empty grid in draw_squares, but return the new grid form the function:
def draw_squares(win, grid, cols, rows):
# nextA = grid # <--- DELETE
nextA = make_2d_array(cols, rows) # <--- ADD
# [...]
return nextA # <-- return the new grid
Make the new grid the current grid by assigning the new grid returned by draw_squares to grid:
grid = draw_squares(WIN, grid, cols, rows)
Additionally the computation of the neighbors is wrong. A field is not a neighbor of itself:
def count_neighbours(grid, x, y):
neighbourCount = 0
for i in range(-1, 2):
for j in range(-1, 2):
if i != 0 or j != 0:
neighbourCount += grid[x + i][y + j]
return neighbourCount

Replace in array of zeros with other values in certain cells_updated question

I need to solve a problem in which I have spent hours, with the data from my excel sheet I have created a 6x36 '' zeros '' matrix of zeros and a 6x6 '' matrix_tran '' coordinate transformation matrix [image 1].
My problem is that I can't find a way to replace the zeros of the '' zeros '' matrix with the values that the matrix '' matrix_tran '' dictates, and whose location must be in the columns (4,5,6, 7,8,9) that are given by the connection vector (4,5,6,7,8,9) of element 15 of the Excel sheet, that is, the last row of the for loop iteration [image 2].
In summary: Below I show how it fits and how it should look [image 3 and 4 respectively].
I would very much appreciate your help, and excuse my English, but it is not my native language, a big greeting.
import pandas as pd
import numpy as np
ex = pd.ExcelFile('matrix_tr.xlsx')
hoja = ex.parse('Hoja1')
cols = 36
for n in range(0,len(hoja)):
A = hoja['ELEMENT #'][n]
B = hoja['1(i)'][n]
C = hoja['2(i)'][n]
D = hoja['3(i)'][n]
E = hoja['1(j)'][n]
F = hoja['2(j)'][n]
G = hoja['3(j)'][n]
H = hoja['X(i)'][n]
I = hoja['Y(i)'][n]
J = hoja['X(j)'][n]
K = hoja['Y(j)'][n]
L = np.sqrt((J-H)**2+(K-I)**2)
lx = (J-H)/L
ly = (K-I)/L
zeros = np.zeros((6, cols))
counters = hoja.loc[:, ["1(i)", "2(i)", "3(i)", "1(j)", "2(j)", "3(j)"]]
for _, i1, i2, i3, j1, j2, j3 in counters.itertuples():
matrix_tran = np.array([[lx, ly, 0, 0, 0, 0],
[-ly, lx, 0, 0, 0, 0],
[0, 0, 1, 0, 0, 0],
[0, 0, 0, lx, ly, 0],
[0, 0, 0, -ly, lx, 0],
[0, 0, 0, 0, 0, 1]])
zeros[:, [i1 - 1, i2 - 1, i3 - 1, j1 - 1, j2 - 1 , j3 - 1]] = matrix_tran

Try with a transposed zeros matrix
import pandas as pd
import numpy as np
ex = pd.ExcelFile('c:/tmp/SO/matrix_tr.xlsx')
hoja = ex.parse('Hoja1')
counters = hoja.loc[:, ["1(i)", "2(i)", "3(i)", "1(j)", "2(j)", "3(j)"]]
# zeros matrix transposed
cols = 36
zeros_trans = np.zeros((cols,6))
# last row only
for n in range(14,len(hoja)):
Xi = hoja['X(i)'][n]
Yi = hoja['Y(i)'][n]
Xj = hoja['X(j)'][n]
Yj = hoja['Y(j)'][n]
X = Xj-Xi
Y = Yj-Yi
L = np.sqrt(X**2+Y**2)
lx = X/L
ly = Y/L
matrix_tran = np.array([[lx, ly, 0, 0, 0, 0],
[-ly, lx, 0, 0, 0, 0],
[0, 0, 1, 0, 0, 0],
[0, 0, 0, lx, ly, 0],
[0, 0, 0, -ly, lx, 0],
[0, 0, 0, 0, 0, 1]])
i = 0
for r in counters.iloc[n]:
zeros_trans[r-1] = matrix_tran[i]
i += 1
print(np.transpose(zeros_trans))