[英]Loop through rows and columns of different data sets in Python
I am new to Python and am struggling to loop through the rows and columns of two different datasets, to generate an array of values.我是 Python 的新手,我正在努力循环遍历两个不同数据集的行和列,以生成一个值数组。
I have two dataframes (parameterMatrix and growthRates);我有两个数据框(parameterMatrix 和growthRates); one shows an array of species and the strengths of their interactions, and the other shows the growth rate of each species.
一个显示了一系列物种及其相互作用的强度,另一个显示了每个物种的生长速度。
parameterMatrix :参数矩阵:
herbivores youngScrub matureScrub sapling matureTree grassHerbs
herbivores 0.0 0.02 0 0.05 0 0.5
youngScrub -0.2 0.00 0 0.00 0 0.0
matureScrub 0.0 0.00 0 0.00 0 0.0
sapling -0.2 0.00 0 0.00 0 0.0
matureTree 0.0 0.00 0 0.00 0 0.0
grassHerbs -5.0 0.00 0 0.00 0 0.0
growthRates :增长率:
herbivores youngScrub matureScrub sapling matureTree grassHerbs
0 0.1 0 0.1 0.1 0 0.2
I am trying to generate an array of values for each of the six species, that can ultimately be used to calculate the rate of change in each species over time.我正在尝试为六个物种中的每一个生成一组值,最终可以用来计算每个物种随时间的变化率。 I have manually written out each of the equations (see below), but I am wondering if there is a faster way to do this, eg by looping through each of these data frames.
我已经手动写出了每个方程(见下文),但我想知道是否有更快的方法来做到这一点,例如通过循环遍历每个数据帧。
def ecoNetwork(X, t=0):
num_herbivores = X[0]
num_youngScrub = X[1]
num_matureScrub = X[2]
num_sapling = X[3]
num_matureTree = X[4]
num_grassHerb = X[5]
return np.array([
# herbivores
(growthRates['herbivores'][0])*num_herbivores + (parameterMatrix['herbivores']['herbivores']*num_herbivores*num_herbivores)
+ (parameterMatrix['herbivores']['youngScrub']*num_herbivores*num_youngScrub)
+ (parameterMatrix['herbivores']['matureScrub']*num_herbivores*num_matureScrub)
+ (parameterMatrix['herbivores']['sapling']*num_herbivores*num_sapling)
+ (parameterMatrix['herbivores']['matureTree']*num_herbivores*num_matureTree)
+ (parameterMatrix['herbivores']['grassHerbs']*num_herbivores*num_grassHerb)
,
# young scrub (X1)
(growthRates['youngScrub'][0])*num_youngScrub + (parameterMatrix['youngScrub']['herbivores']*num_youngScrub*num_herbivores)
+ (parameterMatrix['youngScrub']['youngScrub']*num_youngScrub*num_youngScrub)
+ (parameterMatrix['youngScrub']['matureScrub']*num_youngScrub*num_matureScrub)
+ (parameterMatrix['youngScrub']['sapling']*num_youngScrub*num_sapling)
+ (parameterMatrix['youngScrub']['matureTree']*num_youngScrub*num_matureTree)
+ (parameterMatrix['youngScrub']['grassHerbs']*num_youngScrub*num_grassHerb)
,
# mature scrub
(growthRates['matureScrub'][0])*num_matureScrub + (parameterMatrix['matureScrub']['herbivores']*num_matureScrub*num_herbivores)
+ (parameterMatrix['matureScrub']['youngScrub']*num_matureScrub*num_youngScrub)
+ (parameterMatrix['matureScrub']['matureScrub']*num_matureScrub*num_matureScrub)
+ (parameterMatrix['matureScrub']['sapling']*num_matureScrub*num_sapling)
+ (parameterMatrix['matureScrub']['matureTree']*num_matureScrub*num_matureTree)
+ (parameterMatrix['matureScrub']['grassHerbs']*num_matureScrub*num_grassHerb)
,
# saplings
(growthRates['sapling'][0])*num_sapling + (parameterMatrix['sapling']['herbivores']*num_sapling*num_herbivores)
+ (parameterMatrix['sapling']['youngScrub']*num_sapling*num_youngScrub)
+ (parameterMatrix['sapling']['matureScrub']*num_sapling*num_matureScrub)
+ (parameterMatrix['sapling']['sapling']*num_sapling*num_sapling)
+ (parameterMatrix['sapling']['matureTree']*num_sapling*num_matureTree)
+ (parameterMatrix['sapling']['grassHerbs']*num_sapling*num_grassHerb)
,
# mature trees
(growthRates['matureTree'][0])*num_matureTree + (parameterMatrix['matureTree']['herbivores']*num_matureTree*num_herbivores)
+ (parameterMatrix['matureTree']['youngScrub']*num_matureTree*num_youngScrub)
+ (parameterMatrix['matureTree']['matureScrub']*num_matureTree*num_matureScrub)
+ (parameterMatrix['matureTree']['sapling']*num_matureTree*num_sapling)
+ (parameterMatrix['matureTree']['matureTree']*num_matureTree*num_matureTree)
+ (parameterMatrix['matureTree']['grassHerbs']*num_matureTree*num_grassHerb)
,
# grass & herbaceous plants
(growthRates['grassHerbs'][0])*num_grassHerb + (parameterMatrix['grassHerbs']['herbivores']*num_grassHerb*num_herbivores)
+ (parameterMatrix['grassHerbs']['youngScrub']*num_grassHerb*num_youngScrub)
+ (parameterMatrix['grassHerbs']['matureScrub']*num_grassHerb*num_matureScrub)
+ (parameterMatrix['grassHerbs']['sapling']*num_grassHerb*num_sapling)
+ (parameterMatrix['grassHerbs']['matureTree']*num_grassHerb*num_matureTree)
+ (parameterMatrix['grassHerbs']['grassHerbs']*num_grassHerb*num_grassHerb)
])
# time points
t = np.linspace(0, 50)
# Initial conditions
X0=np.empty(6)
X0[0]= 10
X0[1] = 30
X0[2] = 50
X0[3] = 70
X0[4] = 90
X0[5] = 110
X0 = np.array([X0[0], X0[1], X0[2], X0[3], X0[4], X0[5]])
# Integrate the ODEs
X = integrate.odeint(ecoNetwork, X0, t)
Is this possible and if so, what's the best way to do it?这可能吗?如果可以,最好的方法是什么?
Start by storing your species in a list:首先将您的物种存储在列表中:
species = ["herbivores", "youngScrub", "matureScrub", "sapling", "matureTree", "grassHerbs"]
Then you can loop over this list instead of manually typing out each one:然后,您可以遍历此列表,而不是手动输入每个列表:
new_array = []
for outer_index, outer_animal in enumerate(species):
new_sum = (growthRates[outer_animal][0])* X[outer_index]
for inner_index, inner_animal in enumerate(species):
new_sum += np.sum(parameterMatrix[outer_animal][inner_animal]*X[outer_index]*X[inner_index])
new_array.append(new_sum)
Further out, I'd encourage you to check out pandas
, it's a great python library to work with dataframes.更进一步,我鼓励您查看
pandas
,这是一个很棒的 python 库,可用于处理数据帧。
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