Calcule o vetor resultante da soma dos vetares A, ...

Erstellt am: 14. August 2025

Beantwortet mit GPT-5 Thinking von Chat01

Frage

501706e19c7ad6b7228c50e56afead13.jpeg501706e19c7ad6b7228c50e56afead13.jpeg

Calcule o vetor resultante da soma dos vetares A, B e C e represente o no plano quadriculado abaixo:

Python

python
from PIL import Image, ImageOps, ImageFilter, ImageEnhance, ImageStat, ImageDraw, Image img = Image.open('/mnt/data/501706e19c7ad6b7228c50e56afead13.jpeg') img.size (2006, 2171)

Python

python
img2 = img.copy() display(img2.crop((150,150,1850,1150)).resize((850,500)))

Python

python
display(img2.crop((180,600,520,1000)).resize((500,500)))

Python

python
display(img2.crop((120,520,560,940)).resize((600,400)))

Python

python
display(img2.crop((120,480,700,980)).resize((700,400)))

Python

python
display(img2.crop((520,460,900,900)).resize((500,350)))

Python

python
display(img2.crop((480,420,640,620)).resize((400,300)))

Python

python
display(img2.crop((250,690,430,870)).resize((400,300)))

Python

python
import numpy as np, matplotlib.pyplot as plt, numpy as np crop = img2.crop((150,150,1850,1150)) gray = crop.convert('L') arr = np.array(gray) # Sum columns and rows colsum = arr.mean(axis=0) rowsum = arr.mean(axis=1) # find peaks (low values for dark lines) import numpy as np # Invert to make peaks where lines are darker cols_inv = 255 - colsum rows_inv = 255 - rowsum # Get top peaks by threshold near > mean + 2sd col_thresh = cols_inv.mean() + cols_inv.std()*1.0 row_thresh = rows_inv.mean() + rows_inv.std()*1.0 vline_idx = np.where(cols_inv > col_thresh)[0] hline_idx = np.where(rows_inv > row_thresh)[0] len(vline_idx), len(hline_idx), arr.shape (227, 136, (1000, 1700))

Python

python
def cluster_indices(indices): groups=[] if len(indices)==0: return groups start=indices[0] prev=indices[0] for idx in indices[1:]: if idx==prev+1: prev=idx else: groups.append((start,prev)) start=idx prev=idx groups.append((start,prev)) centers=[(a+b)//2 for a,b in groups if b-a>2] # ignore too thin return centers, groups vcenters,_=cluster_indices(vline_idx) hcenters,_=cluster_indices(hline_idx) len(vcenters), len(hcenters), vcenters[:10], hcenters[:10] (16, 5, [44, 174, 307, 312, 438, 571, 576, 700, 705, 834], [87, 218, 357, 493, 626])

Python

python
def merge_close(centers, tol=10): centers=sorted(centers) merged=[] for c in centers: if not merged or c-merged[-1]>tol: merged.append(c) else: # average merged[-1]=(merged[-1]+c)//2 return merged vcent=merge_close(vcenters, tol=20) hcent=merge_close(hcenters, tol=20) len(vcent), len(hcent), vcent, hcent (12, 5, [44, 174, 309, 438, 573, 702, 836, 969, 1101, 1229, 1363, 1494], [87, 218, 357, 493, 626])

Python

python
import numpy as np, cv2, matplotlib.pyplot as plt # convert to opencv BGR from PIL import numpy as np cv_img = cv2.cvtColor(np.array(crop), cv2.COLOR_RGB2BGR) hsv = cv2.cvtColor(cv_img, cv2.COLOR_BGR2HSV) # dark navy arrow maybe low V and saturation moderate; grid lines are gray. # Try Canny edge detection: edges = cv2.Canny(cv_img, 50, 150) # Try Hough lines probabilistic to detect lines. lines = cv2.HoughLinesP(edges, 1, np.pi/180, threshold=80, minLineLength=150, maxLineGap=10) len(lines) if lines is not None else None 2091

Python

python
import math lines_arr = lines[:,0,:] # compute slopes candidates=[] for x1,y1,x2,y2 in lines_arr: dx=x2-x1; dy=y2-y1 if dx==0: continue slope = -dy/dx # note image coordinates y downward; negative dy upward; slope in cart coords angle = math.degrees(math.atan2(-dy,dx)) # angle from +x axis in standard orientation # A has angle about +40 deg perhaps if 20<angle<70: length=np.hypot(dx,dy) # near left area (x around 250 to 650) if min(x1,x2)<600 and min(y1,y2)>400 and max(y1,y2)<800: candidates.append((length, x1,y1,x2,y2, angle)) len(candidates) 0

Python

python
cand=[] for x1,y1,x2,y2 in lines_arr: dx=x2-x1; dy=y2-y1 if dx==0: continue angle = math.degrees(math.atan2(-(y2-y1), x2-x1)) if 20<angle<70: length=np.hypot(dx,dy) cand.append((length, x1,y1,x2,y2, angle)) len(cand), sorted(cand, reverse=True)[:5][:1] (12, [(1806.0268547283565, 2, 808, 1699, 190, 20.010210819756594)])

Python

python
import matplotlib.pyplot as plt plt.figure(figsize=(8,5)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.show()

Python

python
import matplotlib.pyplot as plt plt.figure(figsize=(4,4)) plt.imshow(crop.crop((400,300,700,650))) for x in vcent: if 400<x<700: plt.axvline(x-400,color='r',alpha=0.4) for y in hcent: if 300<y<650: plt.axhline(y-300,color='b',alpha=0.4) plt.show()

Python

python
plt.figure(figsize=(6,4)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(350,1150); plt.ylim(0,400) plt.gca().invert_yaxis() # but imshow by default flips?

Python

python
plt.figure(figsize=(6,5)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(800,1600); plt.ylim(450,700) plt.show()

Python

python
plt.figure(figsize=(8,6)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(750,1600); plt.ylim(550,700) plt.show()

Python

python
plt.figure(figsize=(8,6)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(750,1600); plt.ylim(450,650) plt.show()

Python

python
plt.figure(figsize=(8,6)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(700,900); plt.ylim(580,660) plt.show()

Python

python
plt.figure(figsize=(7,5)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(820,900); plt.ylim(610,660) plt.show()

Python

python
plt.figure(figsize=(8,6)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(1300,1600); plt.ylim(350,550) plt.show()

Python

python
# crop bottom grid bot = img2.crop((80,1060,1700,2000)) display(bot.resize((800,500))) # detect vertical line centers bg = bot.convert('L') arr = np.array(bg) cols_inv = 255 - arr.mean(axis=0) rows_inv = 255 - arr.mean(axis=1) col_thresh = cols_inv.mean() + cols_inv.std()*0.7 row_thresh = rows_inv.mean() + rows_inv.std()*0.7 vline_idx = np.where(cols_inv > col_thresh)[0] hline_idx = np.where(rows_inv > row_thresh)[0] vcenters,_=cluster_indices(vline_idx) hcenters,_=cluster_indices(hline_idx) vcent=merge_close(vcenters, tol=20) hcent=merge_close(hcenters, tol=20) len(vcent), len(hcent), vcent[:10], hcent[:10] (13, 7, [63, 130, 262, 390, 521, 649, 779, 906, 1034, 1165], [116, 248, 375, 505, 633, 757, 885])

Python

python
plt.figure(figsize=(5,4)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(400,520); plt.ylim(60,140) plt.show()

Python

python
plt.figure(figsize=(5,4)) plt.imshow(crop) for x in vcent: plt.axvline(x,color='r',alpha=0.3) for y in hcent: plt.axhline(y,color='b',alpha=0.3) plt.xlim(1030,1120); plt.ylim(185,225) plt.show()

Python

python
# Recompute grid lines for bot with better thresholds and not trimming edges bg = bot.convert('L') arr = np.array(bg) cols_inv = 255 - arr.mean(axis=0) rows_inv = 255 - arr.mean(axis=1) # Use more conservative threshold col_thresh = cols_inv.mean() + cols_inv.std()*0.8 row_thresh = rows_inv.mean() + rows_inv.std()*0.8 vline_idx = np.where(cols_inv > col_thresh)[0] hline_idx = np.where(rows_inv > row_thresh)[0] vcenters,_=cluster_indices(vline_idx) hcenters,_=cluster_indices(hline_idx) vcent=merge_close(vcenters, tol=20) hcent=merge_close(hcenters, tol=20) len(vcent), len(hcent), vcent[:], hcent[:] (13, 7, [63, 131, 263, 390, 521, 649, 779, 906, 1034, 1165, 1291, 1417, 1546], [116, 248, 375, 505, 632, 757, 885])

Gedanke

Recompute grid lines for bot with better thresholds and not trimming edges

bg = bot.convert('L') arr = np.array(bg) cols_inv = 255 - arr.mean(axis=0) rows_inv = 255 - arr.mean(axis=1)

Use more conservative threshold

col_thresh = cols_inv.mean() + cols_inv.std()*0.8 row_thresh = rows_inv.mean() + rows_inv.std()*0.8 vline_idx = np.where(cols_inv > col_thresh)[0] hline_idx = np.where(rows_inv > row_thresh)[0] vcenters,=cluster_indices(vline_idx) hcenters,=cluster_indices(hline_idx) vcent=merge_close(vcenters, tol=20) hcent=merge_close(hcenters, tol=20) len(vcent), len(hcent), vcent[:], hcent[:]

(13, 7, [63, 131, 263, 390, 521, 649, 779, 906, 1034, 1165, 1291, 1417, 1546], [116, 248, 375, 505, 632, 757, 885])

Thought for 7m 36s

Python

python
from PIL import Image, ImageDraw # Load the original photo and crop the lower (blank) grid img = Image.open("/mnt/data/501706e19c7ad6b7228c50e56afead13.jpeg") lower_grid = img.crop((150, 1180, 1850, 2100)) # manual crop tuned to the blank grid # Measure grid lines to place the vector precisely import numpy as np gray = lower_grid.convert("L") arr = np.array(gray) cols_inv = 255 - arr.mean(axis=0) rows_inv = 255 - arr.mean(axis=1) # Find vertical and horizontal grid line centers def cluster_indices(indices): groups=[] if len(indices)==0: return [] start=indices[0]; prev=indices[0] for idx in indices[1:]: if idx==prev+1: prev=idx else: groups.append((start,prev)); start=idx; prev=idx groups.append((start,prev)) centers=[(a+b)//2 for a,b in groups if b-a>2] return centers def merge_close(centers, tol=20): centers=sorted(centers) merged=[] for c in centers: if not merged or c-merged[-1]>tol: merged.append(c) else: merged[-1]=(merged[-1]+c)//2 return merged col_thresh = cols_inv.mean() + cols_inv.std()*0.8 row_thresh = rows_inv.mean() + rows_inv.std()*0.8 vcenters = merge_close(cluster_indices(np.where(cols_inv > col_thresh)[0]), tol=20) hcenters = merge_close(cluster_indices(np.where(rows_inv > row_thresh)[0]), tol=20) # Choose origin at bottom-left interior intersection origin = (vcenters[0], hcenters[-1]) # Resultant R = (12, 3) grid units (right, up) # Convert grid steps to pixel coordinates using detected line centers end = (vcenters[12], hcenters[-1-3]) # 12 right, 3 up # Draw the vector out = lower_grid.copy() draw = ImageDraw.Draw(out) draw.line([origin, end], width=10) # default color (black) # Arrowhead import math x1,y1 = origin; x2,y2 = end angle = math.atan2(y2-y1, x2-x1) arrow_len = 30 wing = 12 p1 = (x2 - arrow_len*math.cos(angle) + wing*math.sin(angle), y2 - arrow_len*math.sin(angle) - wing*math.cos(angle)) p2 = (x2 - arrow_len*math.cos(angle) - wing*math.sin(angle), y2 - arrow_len*math.sin(angle) + wing*math.cos(angle)) draw.polygon([end, p1, p2], outline=None, fill=None) # Save out_path = "/mnt/data/resultante_R_12x3.png" out.save(out_path) out, out_path

Python

python
from PIL import Image, ImageDraw import numpy as np, math # Load and crop the lower grid a bit wider to include borders img = Image.open("/mnt/data/501706e19c7ad6b7228c50e56afead13.jpeg") lower_grid = img.crop((80, 1160, 1850, 2100)) # Detect grid lines (centers) gray = lower_grid.convert("L") arr = np.array(gray) cols_inv = 255 - arr.mean(axis=0) rows_inv = 255 - arr.mean(axis=1) def cluster_indices(indices): groups=[] if len(indices)==0: return [] start=indices[0]; prev=indices[0] for idx in indices[1:]: if idx==prev+1: prev=idx else: groups.append((start,prev)); start=idx; prev=idx groups.append((start,prev)) centers=[(a+b)//2 for a,b in groups if b-a>2] return centers def merge_close(centers, tol=20): centers=sorted(centers) merged=[] for c in centers: if not merged or c-merged[-1]>tol: merged.append(c) else: merged[-1]=(merged[-1]+c)//2 return merged col_thresh = cols_inv.mean() + cols_inv.std()*0.8 row_thresh = rows_inv.mean() + rows_inv.std()*0.8 vcenters = merge_close(cluster_indices(np.where(cols_inv > col_thresh)[0]), tol=20) hcenters = merge_close(cluster_indices(np.where(rows_inv > row_thresh)[0]), tol=20) # Choose origin and end: R = (12, 3) steps (right, up) # If the crop misses an edge line, cap the index to the last available. origin = (vcenters[0], hcenters[-1]) end_v_index = min(12, len(vcenters)-1) end_h_index = max(0, len(hcenters)-1-3) end = (vcenters[end_v_index], hcenters[end_h_index]) # Draw the vector out = lower_grid.copy() draw = ImageDraw.Draw(out) draw.line([origin, end], width=10) # default color # Arrowhead x1,y1 = origin; x2,y2 = end angle = math.atan2(y2-y1, x2-x1) arrow_len = 30 wing = 12 p1 = (x2 - arrow_len*math.cos(angle) + wing*math.sin(angle), y2 - arrow_len*math.sin(angle) - wing*math.cos(angle)) p2 = (x2 - arrow_len*math.cos(angle) - wing*math.sin(angle), y2 - arrow_len*math.sin(angle) + wing*math.cos(angle)) draw.polygon([end, p1, p2]) out_path = "/mnt/data/resultante_R_12x3.png" out.save(out_path) out, out_path (<PIL.Image.Image image mode=RGB size=1770x940>, '/mnt/data/resultante_R_12x3.png')

Antwort

Vamos somar por componentes (em “quadradinhos”):

  • A\vec A: +2+2 para a direita e +2+2 para cima → (2,2)(2,\,2)
  • B\vec B: +5+5 para a direita e 11 para baixo(5,1)(5,\,-1)
  • C\vec C: +5+5 para a direita e +2+2 para cima → (5,2)(5,\,2)

Resultante:

R=A+B+C=(2+5+5,  21+2)=(  12,  3  )\vec R=\vec A+\vec B+\vec C=(2+5+5,\;2-1+2)=(\;12,\;3\;)

Ou seja, 12 quadrados para a direita e 3 para cima.
Módulo: R=122+32=15312,37|\vec R|=\sqrt{12^2+3^2}=\sqrt{153}\approx 12{,}37 (em unidades da malha).
Ângulo: θ=arctan ⁣(312)14\theta=\arctan\!\left(\frac{3}{12}\right)\approx 14^\circ acima do eixo horizontal.

Desenhei R\vec R no plano quadriculado de baixo (partindo do canto inferior esquerdo da malha):

[Baixar a imagem com o vetor resultante]

Se preferir que a seta comece de outro ponto, digo onde ficam a cauda e a ponta.

Diesen Q&A teilen