t(m+1) = y_sort_new(m)((1-p0)*length(x_sort_new(m+1)));使用括号 '()' 进行索引必须作为有效索引表达式的最后一个操作出现。怎么改正？

您可以将括号 '()' 中的表达式提取出来并赋值给一个变量，然后使用该变量作为索引表达式的最后一个操作。例如：

index = (1-p0)*length(x_sort_new(m+1));
t(m+1) = y_sort_new(m)(index);

这样就可以避免出现使用括号 '()' 进行索引的错误。

相关问题

brier_efron <- function(y_train_true, y_train_pred, y_newdata, y_newdata_pred, times){ baseline <- base_efron(y_train_true, y_train_pred) y_newdata <- data.frame(y_newdata) colnames(y_newdata) = c("time","event") new_index <- order(y_newdata$time) y_newdata <- y_newdata[new_index,] y_newdata_pred <- y_newdata_pred[new_index,] Y_x = sapply(times, function(x){as.integer(y_newdata$time > x)}) ipcw <- pec::ipcw(formula = as.formula(Surv(time, event) ~ 1), data = y_newdata, method = "marginal", times = times, subjectTimes = y_newdata$time, subjectTimesLag = 1) G_t = ipcw$IPCW.times G_x = ipcw$IPCW.subjectTimes W_x = matrix(NA, nrow = nrow(y_newdata), ncol = length(times)) for (t in 1:length(times)) { W_x[,t] = (1-Y_x[,t])*y_newdata$event/G_x + Y_x[,t]/G_t[t] } Lambda_t = sapply(times, function(x){baseline$cumhazard$hazard[sum(baseline$cumhazard$time <= x)] }) S_x = exp(-1 * exp(y_newdata_pred) %*% matrix(Lambda_t, nrow = 1)) BS_t = sapply(1:length(times), function(x) {mean(W_x[,x] * (Y_x[,x] - S_x[,x])^2)}) return(list(bs = data.frame(time=times, bs=BS_t))) } 改成python代码

以下是将R代码转换为Python代码的版本：

import numpy as np
import pandas as pd
from lifelines import CoxPHFitter
from lifelines.utils import concordance_index
from lifelines import KaplanMeierFitter

def brier_efron(y_train_true, y_train_pred, y_newdata, y_newdata_pred, times):

    baseline = base_efron(y_train_true, y_train_pred)

    y_newdata = pd.DataFrame(y_newdata, columns=["time", "event"])
    y_newdata = y_newdata.sort_values(by="time")
    y_newdata_pred = y_newdata_pred[y_newdata.index]

    Y_x = np.zeros((len(y_newdata), len(times)))
    for i, x in enumerate(times):
        Y_x[:, i] = np.where(y_newdata["time"] > x, 1, 0)

    kmf = KaplanMeierFitter().fit(y_newdata["time"], event_observed=y_newdata["event"])
    G_t = kmf.survival_function_at_times(times).values.flatten()
    G_x = kmf.predict(y_newdata["time"]).values.flatten()

    W_x = np.zeros((len(y_newdata), len(times)))
    for t in range(len(times)):
        W_x[:, t] = (1 - Y_x[:, t]) * y_newdata["event"] / G_x + Y_x[:, t] / G_t[t]

    Lambda_t = [baseline.baseline_hazard_[baseline.baseline_survival_.index(baseline.baseline_survival_.index <= x)].sum() for x in times]
    S_x = np.exp(-np.exp(y_newdata_pred) @ np.array(Lambda_t))

    BS_t = [np.mean(W_x[:, x] * (Y_x[:, x] - S_x[:, x])**2) for x in range(len(times))]

    return pd.DataFrame({"time": times, "bs": BS_t})

请注意，这个转换过程中使用了lifelines库，该库提供了在Python中进行生存分析的功能。因此，你需要在运行代码之前确保已安装lifelines库。另外，请注意在Python中的一些细微差异，例如使用`pd.DataFrame`来创建数据框，使用`@`来进行矩阵乘法等。

function SuffixArray(str) { var s = str; var n = str.length; var sa = new Array(n), rank = new Array(n), height = new Array(n), x = new Array(n), y = new Array(n), m = 256, c = new Array(m); for (var i = 0; i < m; i++) c[i] = 0; for (var i = 0; i < n; i++) c[rank[i] = s.charCodeAt(i)]++; for (var i = 1; i < m; i++) c[i] += c[i - 1]; for (var i = n - 1; i >= 0; i--) sa[--c[rank[i]]] = i; for (var k = 1; k <= n; k <<= 1) { for (var i = n - k, p = 0; i < n; i++) x[p++] = i; for (var i = 0; i < n; i++) if (sa[i] >= k) x[p++] = sa[i] - k; for (var i = 0; i < m; i++) c[i] = 0; for (var i = 0; i < n; i++) c[rank[x[i]]]++; for (var i = 1; i < m; i++) c[i] += c[i - 1]; for (var i = n - 1; i >= 0; i--) sa[--c[rank[x[i]]]] = x[i]; for (var t = rank,rank = y,y = t,p = rank[sa[0]] = 0, i = 1; i < n; i++) { rank[sa[i]] = (y[sa[i]] == y[sa[i - 1]] && y[sa[i] + k] == y[sa[i - 1] + k]) ? p : ++p; } if (p >= n - 1) break; m = p + 1; } for (var k = i =0;i<n;++i){ if(rank[i]==0) continue; if(k) --k; var j=sa[rank[i]-1]; while(i+k<n && j+k<n && s.charAt(i+k)==s.charAt(j+k)) ++k; height[rank[i]]=k; } return { sa: sa, rank: rank, height: height }; } 这个函数创建后缀数组的能不能用DC3实现了，帮我修改为DC3算法可以吗

好的，这里是使用DC3算法实现后缀数组的代码：

function SuffixArray(str) {
var s = str;
var n = str.length;
var sa = new Array(n);
var rank = new Array(n);
var height = new Array(n);
var x = new Array(n);
var y = new Array(n);
var m = 256;
var c = new Array(m);

function sort_doubling(sa, rank, height, n, m) {
var tmp = new Array(n);
var i, j, p;
for (i = 0; i < m; ++i) c[i] = 0;
for (i = 0; i < n; ++i) c[x[i] = s.charCodeAt(i)]++;
for (i = 1; i < m; ++i) c[i] += c[i - 1];
for (i = n - 1; i >= 0; --i) sa[--c[x[i]]] = i;
for (j = p = 1; p < n; j <<= 1, m = p) {
for (p = 0, i = n - j; i < n; ++i) y[p++] = i;
for (i = 0; i < n; ++i) if (sa[i] >= j) y[p++] = sa[i] - j;
for (i = 0; i < m; ++i) c[i] = 0;
for (i = 0; i < n; ++i) c[x[y[i]]]++;
for (i = 1; i < m; ++i) c[i] += c[i - 1];
for (i = n - 1; i >= 0; --i) sa[--c[x[y[i]]]] = y[i];
for (tmp[sa[0]] = 0, i = 1, p = 1; i < n; ++i) {
if (x[sa[i]] == x[sa[i - 1]] && x[sa[i] + j] == x[sa[i - 1] + j]) {
tmp[sa[i]] = p - 1;
} else {
tmp[sa[i]] = p++;
}
}
for (i = 0; i < n; ++i) x[i] = tmp[i];
if (p >= n) break;
}
for (i = 0; i < n; ++i) rank[sa[i]] = i;
for (i = j = 0; i < n; ++i) {
if (rank[i]) {
if (j) --j;
var k = sa[rank[i] - 1];
while (i + j < n && k + j < n && s.charAt(i + j) == s.charAt(k + j)) ++j;
height[rank[i]] = j;
}
}
}

function sort_triples(Y, SA, n, K) {
var i, j;
if (K <= 1) {
for (i = 0; i < n; ++i) SA[i] = i;
} else {
var t = new Array(n + 3);
for (i = 0; i < n + 3; ++i) t[i] = 0;
for (i = 0; i < n; ++i) t[Y[i]]++;
for (i = 1; i < K; ++i) t[i] += t[i - 1];
for (i = 0; i < n; ++i) SA[--t[Y[i]]] = i;
for (j = 1; j < K; ++j) {
var p = 0;
for (i = n - j; i < n; ++i) y[p++] = i;
for (i = 0; i < n; ++i) if (SA[i] >= j) y[p++] = SA[i] - j;
for (i = 0; i < n + 3; ++i) t[i] = 0;
for (i = 0; i < n; ++i) t[x[i] = Y[i]]++;
for (i = 1; i < n + 3; ++i) t[i] += t[i - 1];
for (i = n - 1; i >= 0; --i) SA[--t[x[y[i]]]] = y[i];
var swap = x;
x = y;
y = swap;
p = 1;
x[SA[0]] = 0;
for (i = 1; i < n; ++i) {
var a = SA[i - 1], b = SA[i];
var cmp = ((Y[a] == Y[b]) && (Y[a + j] == Y[b + j]));
x[SA[i]] = cmp ? p - 1 : p++;
}
if (p >= n) break;
K = p;
}
}
}

function dc3(SA, s, n, K) {
var i, j, *y = new int[n + 3], * SA12 = new int[n / 3 + 1], * y12 = new int[n / 3 + 1], * SA0 = new int[n / 3], * y0 = new int[n / 3], c0, c1, c2;
s[n] = s[n + 1] = s[n + 2] = 0;
for (i = 0, j = 0; i < n; ++i) {
if (i % 3 != 0) y[j++] = i;
}
sort_triples(y, SA12, j, K);
for (i = 0; i < j; ++i) y12[SA12[i]] = i + 1;
for (i = 0, j = 0; i < n; ++i) {
if (i % 3 == 1) {
y0[j++] = i;
}
}
sort_doubling(SA0, y0, new int[j], j, K);
for (i = 0, j = 0, c0 = c1 = c2 = -1; i < n; ++i) {
if (i % 3 == 1) {
var p0 = SA0[j];
var p1 = (p0 < n - 1) ? y[p0 + 1] : -1;
var p2 = (p0 < n - 2) ? y[p0 + 2] : -1;
int cmp;
if ((cmp = (y[p0] == c0 ? y[p1] == c1 ? y[p2] == c2 ? 0 : 1 : 0 : 0)) == 1) {
SA[i] = p0;
++j;
} else {
SA[i] = n + SA12[y12[p0 / 3] + (cmp == 0 ? 0 : SA12.length)];
}
} else if (i % 3 == 2) {
var p0 = SA12[y[i / 3]];
var p1 = (p0 < n - 1) ? y[p0 + 1] : -1;
var p2 = (p0 < n - 2) ? y[p0 + 2] : -1;
int cmp;
if ((cmp = (y[p0] == c0 ? y[p1] == c1 ? y[p2] == c2 ? 0 : 1 : 0 : 0)) == 1) {
SA[i] = p0;
} else {
SA[i] = n + SA0[y0[p0 / 3] + (cmp == 0 ? 0 : SA0.length)];
}
}
}
delete[] y;
delete[] SA12;
delete[] y12;
delete[] SA0;
delete[] y0;
}

dc3(sa, s, n, m);
return {
sa: sa,
rank: rank,
height: height
};
}