如何遍历Python坐标二维列表并对应修改y轴数值

Hey Calvin! Sounds like you've already nailed the x-axis grouping part—great job getting that sorted. Now let's get those y-values mapped to the -5 to 5 range as needed. I'll walk you through two common approaches depending on how you want the y-axis distributed:

Option 1: Linear Y-Value Distribution (Smooth Range) #

If you want every coordinate's y-value to smoothly span from -5 to 5 across all 100 elements (so the first element has y=-5, last has y=5, and everything in between scales linearly), here's a straightforward way to do it:

# Assume your pre-processed coordinate list is named coords
y_min = -5
y_max = 5
total_coords = len(coords)

for idx in range(total_coords):
    # Map the index (0-99) to the y range using linear interpolation
    mapped_y = y_min + (y_max - y_min) * (idx / (total_coords - 1))
    coords[idx][1] = mapped_y

Or if you prefer a more concise list comprehension:

y_min, y_max = -5, 5
total = len(coords)
coords = [[x, y_min + (y_max - y_min)*(i/(total-1))] for i, (x, _) in enumerate(coords)]

Option 2: Grouped Y-Values (Per X-Group Fixed Y) #

If you want each group of 10 coordinates (sharing the same x-value) to have a fixed y-value that increments from -5 to 5 (e.g., first x-group [-5,y] gets y=-5, next [-4,y] gets y=-4, etc.), use this approach:

coords = [...]  # Your existing list with x-values sorted into groups
num_groups = 10  # Since 100 elements = 10 groups of 10
y_start = -5
y_end = 5

# Calculate the step between each group's y-value
y_step = (y_end - y_start) / (num_groups - 1) if num_groups > 1 else 0

for group_num in range(num_groups):
    # Define the start/end indices for the current group
    group_start = group_num * 10
    group_end = group_start + 10
    # Compute the y-value for this group
    current_y = y_start + group_num * y_step
    # Update every coordinate in the group
    for coord in coords[group_start:group_end]:
        coord[1] = current_y

Note: If your x-axis actually uses 11 groups (to cover from -5 to 5 inclusive with integer steps), just change num_groups to 11—this will adjust the y-step automatically to span -5 to 5 across 11 groups.

内容的提问来源于stack exchange，提问作者calvin fraser