将一系列值映射到另一个值

一种解决办法是:

def translate(value, leftMin, leftMax, rightMin, rightMax):
    # Figure out how 'wide' each range is
    leftSpan = leftMax - leftMin
    rightSpan = rightMax - rightMin

    # Convert the left range into a 0-1 range (float)
    valueScaled = float(value - leftMin) / float(leftSpan)

    # Convert the 0-1 range into a value in the right range.
    return rightMin + (valueScaled * rightSpan)

使用scipy.interpolate.interp1d

你也可以使用 scipy.interpolate 包进行此类转换(如果您不介意依赖于SciPy):

>>> from scipy.interpolate import interp1d
>>> m = interp1d([1,512],[5,10])
>>> m(256)
array(7.4951076320939336)

>>> float(m(256))
7.4951076320939336

您还可以在一个命令中轻松地执行多个转换:

>>> m([100,200,300])
array([ 5.96868885,  6.94716243,  7.92563601])

作为奖励,您可以从一个范围到另一个范围进行非均匀映射,例如,如果您想将[1128]映射到[1,10]、[128256]映射到[10,90]和[256512]映射到[90100],您可以这样做:

>>> m = interp1d([1,128,256,512],[1,10,90,100])
>>> float(m(400))
95.625

interp1d 创建分段线性插值对象(与函数一样可调用)。

正如 ~unutbu , numpy.interp

>>> from numpy import interp
>>> interp(256,[1,512],[5,10])
7.4951076320939336

相反,请尝试以下方法:

def make_interpolater(left_min, left_max, right_min, right_max): 
    # Figure out how 'wide' each range is  
    leftSpan = left_max - left_min  
    rightSpan = right_max - right_min  

    # Compute the scale factor between left and right values 
    scaleFactor = float(rightSpan) / float(leftSpan) 

    # create interpolation function using pre-calculated scaleFactor
    def interp_fn(value):
        return right_min + (value-left_min)*scaleFactor

    return interp_fn

# create function for doing interpolation of the desired
# ranges
scaler = make_interpolater(1, 512, 5, 10)

# receive list of raw values from sensor, assign to data_list

# now convert to scaled values using map 
scaled_data = map(scaler, data_list)

# or a list comprehension, if you prefer
scaled_data = [scaler(x) for x in data_list]

我在python中寻找同样的东西,将角度0-300deg映射到原始dynamixel值0-1023或1023-0,具体取决于执行器方向。

变量:

x:input value; 
a,b:input range
c,d:output range
y:return value

功能:

def mapFromTo(x,a,b,c,d):
   y=(x-a)/(b-a)*(d-c)+c
   return y

dyn111.goal_position=mapFromTo(pos111,0,300,0,1024)

def translate(sensor_val, in_from, in_to, out_from, out_to):
    out_range = out_to - out_from
    in_range = in_to - in_from
    in_val = sensor_val - in_from
    val=(float(in_val)/in_range)*out_range
    out_val = out_from+val
    return out_val

def maprange(a, b, s):
    (a1, a2), (b1, b2) = a, b
    return  b1 + ((s - a1) * (b2 - b1) / (a2 - a1))


a = [from_lower, from_upper]
b = [to_lower, to_upper]

发现于 https://rosettacode.org/wiki/Map_range#Python_

• a 或 b (它推断)
• 也适用于 from_lower > from_upper to_lower > to_upper

简单地图范围功能:

def mapRange(value, inMin, inMax, outMin, outMax):
    return outMin + (((value - inMin) / (inMax - inMin)) * (outMax - outMin))