R 在矩阵中找到一个子矩阵
我有一个矩阵，比如：R 在矩阵中找到一个子矩阵,r,matrix,R,Matrix,我有一个矩阵，比如： df<-data.frame(a=c(1,2,5,4,5,4), b=c(3,4,8,6,7,4)) 但不是完全的矩阵。我需要得到大矩阵中子矩阵的坐标。在这种情况下，将是 (5,1;6,2) 有没有一种不用循环就能解决这个问题的方法？我不知道你的答案（3，1；4，2）是否正确，但这就是我提出的解决方案： mapply(function(x, y) which(x %in% y), df, df1) a b [1,] 3 2 [2,] 5 4 老实说，我
df<-data.frame(a=c(1,2,5,4,5,4), b=c(3,4,8,6,7,4))
(5,1;6,2)
有没有一种不用循环就能解决这个问题的方法？我不知道你的答案
（3，1；4，2）mapply(function(x, y) which(x %in% y), df, df1)
a b
[1,] 3 2
[2,] 5 4
老实说，我真的不认为有办法避免循环：
# find all matches of the top left corner of df1
hits <- which(df==df1[1,1],arr.ind=TRUE)
# remove those matches that can't logically fit in the data
hits <- hits[hits[,"row"] <= nrow(df)-nrow(df1)+1,,drop=FALSE]
# check which of the matches is a hit...
# returning the top left corner of where the match is
hits[apply(
hits,
1,
function(x)
all(df[matrix(c(x,x+1:0,x+0:1,x+1),ncol=2,byrow=TRUE)] == unlist(df1))
)]
#[1] 5 1
#查找df1左上角的所有匹配项
hits是解决这类问题的好工具
我在这里有点过火了，写了一个非常复杂的函数，可以找到一个较大数组中较小数组的所有匹配的最低索引（对于矩阵是左上角）角的坐标，对于任何维度。如果要在11维数组中查找9维数组的所有位置，此函数可以为您完成
这是：
library('Rcpp');
cppFunction('
IntegerMatrix findarray(IntegerVector big, IntegerVector small, bool nacmp=true ) {
// debugging macros
#define QUOTEID(...) #__VA_ARGS__
#define QUOTE(...) QUOTEID(__VA_ARGS__)
#define PRINT_VEC(vec,...) Rprintf(QUOTE(vec)"={"); if (vec.size() > 0) { Rprintf("%ld",vec[0]); for (size_t i = 1; i < vec.size(); ++i) Rprintf(",%ld",vec[i]); } Rprintf("}"__VA_ARGS__);
typedef std::vector<size_t> Dims;
// get big dimensions, treating a plain vector as a 1D array
Dims bigdims;
SEXP bigdimsSE = big.attr("dim");
if (Rf_isNull(bigdimsSE)) {
bigdims.push_back(big.size());
} else {
bigdims = as<Dims>(bigdimsSE);
}
//PRINT_VEC(bigdims,"\\n");
// now we can use this macro to easily return a result matrix with no matches
#define RES_NOMATCH IntegerMatrix(0,bigdims.size())
// get small dimensions, treating a plain vector as a 1D array
Dims smalldims;
SEXP smalldimsSE = small.attr("dim");
if (Rf_isNull(smalldimsSE)) {
smalldims.push_back(small.size());
} else {
smalldims = as<Dims>(smalldimsSE);
}
//PRINT_VEC(smalldims,"\\n");
// trivial case: if small has greater dimensionality than big, just return no matches
// note: we could theoretically support this case, at least when all extra small dimensions have only one index, but whatever
if (smalldims.size() > bigdims.size())
return RES_NOMATCH;
// derive a "bounds" Dims object, which will represent the maximum index plus one in big against which we must compare the first index in small for the corresponding dimension
// if small is greater than big in any dimension, then we can return no matches immediately
Dims bounds(smalldims.size());
for (size_t i = 0; i < smalldims.size(); ++i) {
if (smalldims[i] > bigdims[i])
return RES_NOMATCH;
bounds[i] = bigdims[i]-smalldims[i]+1;
}
// trivial case: if either big or small has any zero-length dimension, then just return no matches, because in that case the offending argument cannot have any actual data in it
// theoretically you can consider such degenerate arrays to match everywhere, sort of like the empty string matching at every position in any given string, but whatever
for (size_t i = 0; i < bigdims.size(); ++i) if (bigdims[i] == 0) return RES_NOMATCH;
for (size_t i = 0; i < smalldims.size(); ++i) if (smalldims[i] == 0) return RES_NOMATCH;
// prepare to build up the result data
// it would not make sense to build up the result data directly in a matrix, because we have to add one row at a time, which does not commute with the internal storage arrangement of matrices
// I then tried to use a data.frame, but the Rcpp DataFrame type is surprisingly light in functionality, seemingly without any provision for adding a row, and requires named columns, so best to avoid that
// instead, we\'ll just build up the data on a vector of vectors, going all-STL
typedef std::vector<std::vector<int> > ResBuilder;
ResBuilder resBuilder(bigdims.size());
// retrieve raw vector pointers for best performance
int* bigp = INTEGER(big);
int* smallp = INTEGER(small);
// now, iterate through each index of each (big) dimension from zero through the bound for that dimension (which is automatically the big dimension\'s length if small\'s dimensionality does not extend to that dimension), and see if small\'s first element matches
Dims bdis(bigdims.size()); // conveniently, initializes to all zeroes
size_t bvi = 0; // big vector index
while (true) { // big element loop, restricted to bounds
if (bigp[bvi] == smallp[0] && (nacmp || bigp[bvi] != NA_INTEGER)) {
//PRINT_VEC(bdis," ") Rprintf("found first element match at bvi=%ld big=small=%d\\n",bvi,bigp[bvi]);
size_t bvi2 = bvi; // don\'t screw up the original bvi; matches can overlap
// now we need to iterate through each index of each (small) dimension and test if all remaining elements match
Dims sdis(smalldims.size()); // conveniently, initializes to all zeroes
size_t svi = 0;
bool match = true; // assumption
while (true) { // small element loop
// note: once inside this inner loop, we don\'t have to worry about bounds anymore, because we already enforced that the outer loop will only iterate over indexes within bounds
// increment small and big indexes
++svi; // always increment svi by exactly one; the small array governs this matching loop
//PRINT_VEC(bdis," ") PRINT_VEC(sdis," ") Rprintf("incremented svi=%ld\\n",svi);
size_t bm = 1;
size_t d;
for (d = 0; d < sdis.size(); ++d) {
++sdis[d];
++bvi2;
if (sdis[d] == smalldims[d]) {
//PRINT_VEC(bdis," ") PRINT_VEC(sdis," ") Rprintf("reached small end=%ld of dimension d=%ld; bvi2=%ld bm=%ld\\n",smalldims[d],d,bvi2,bm);
sdis[d] = 0;
bvi2 += (bigdims[d]-smalldims[d])*bm-1;
bm *= bigdims[d];
//PRINT_VEC(bdis," ") PRINT_VEC(sdis," ") Rprintf("after jumping to next index we have bvi2=%ld bm=%ld\\n",bvi2,bm);
} else {
//PRINT_VEC(bdis," ") PRINT_VEC(sdis," ") Rprintf("valid dimension index increment at dimension d=%ld; bvi2=%ld bm=%ld\\n",d,bvi2,bm);
break;
}
}
// test if we reached the end of small; then break the inner while loop, and we have a match
if (d == sdis.size())
break;
// at this point, we have a new element to test; if unequal, we have no match
if (bigp[bvi2] != smallp[svi] || !nacmp && bigp[bvi] == NA_INTEGER) {
//PRINT_VEC(bdis," ") PRINT_VEC(sdis," ") Rprintf("match overturned by big=%d != small=%d\\n",bigp[bvi2],smallp[svi]);
match = false;
break;
} else {
//PRINT_VEC(bdis," ") PRINT_VEC(sdis," ") Rprintf("match respected by big=small=%d\\n",bigp[bvi2]);
}
}
// if we have a match, add it to the result data
if (match) {
//PRINT_VEC(bdis," ") Rprintf("found complete match!\\n");
for (size_t bd = 0; bd < bigdims.size(); ++bd)
resBuilder[bd].push_back(bdis[bd]+1); // also add one to convert from C++ zero-based to R one-based indexes
//PRINT_VEC(bdis," ") Rprintf("resBuilder dims = {%ld,%ld}\\n",resBuilder[0].size(),resBuilder.size());
}
} else {
//PRINT_VEC(bdis," ") Rprintf("first element mismatch: big=%d != small=%d\\n",bigp[bvi],smallp[0]);
}
// increment big index
size_t bm = 1;
size_t d;
for (d = 0; d < bdis.size(); ++d) {
++bdis[d];
++bvi;
size_t bound = bounds.size() > d ? bounds[d] : bigdims[d];
if (bdis[d] >= bound) {
//PRINT_VEC(bdis," ") Rprintf("big index hit bound=%ld of dimension d=%ld; bvi=%ld bm=%ld\\n",bound,d,bvi,bm);
bdis[d] = 0;
bvi += (bigdims[d]-bound)*bm-1;
bm *= bigdims[d];
//PRINT_VEC(bdis," ") Rprintf("after advancing big index we have bvi=%ld bm=%ld\\n",bvi,bm);
} else {
//PRINT_VEC(bdis," ") Rprintf("valid dimension index increment at dimension d=%ld; bvi=%ld bm=%ld\\n",d,bvi,bm);
break;
}
}
// test if we reached the end of big; then break the outer while loop, and we\'re done
if (d == bdis.size() || bvi >= big.size())
break;
}
// copy to a matrix
IntegerMatrix res(resBuilder[0].size(),resBuilder.size());
int* resp = INTEGER(res);
for (size_t c = 0; c < res.ncol(); ++c)
std::copy(resBuilder[c].begin(),resBuilder[c].end(),resp+c*res.nrow());
// return the matrix
return res;
}
');
下面是关于您的数据的演示：
df <- data.frame(a=c(1,2,5,4,5,4),b=c(3,4,8,6,7,4));
df1 <- data.frame(a=c(5,4),b=c(7,4));
findarray(as.matrix(df),as.matrix(df1));
## [,1] [,2]
## [1,] 5 1
注意，换位是必要的，因为R将短向量循环到一个较大的矩阵上（即跨行，然后跨列）。这对于您的特定数据显然不是必需的，因为只有一个匹配项，而且df1
的两个维度具有相同的长度，因此这并不重要，但在一般情况下很重要
好的，我可以这么说，这里有一个简单的测试，可以在11D阵列中匹配9D：
set.seed(12);
big <- array(sample(1:4,factorial(11),replace=T),11:1);
small <- array(sample(1:4,12,replace=T),c(2,3,2,rep(1,9-3)));
res <- findarray(big,small);
res;
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## [1,] 6 6 5 3 1 3 4 3 2 1 1
## [2,] 7 7 6 3 5 6 5 4 3 2 1
sapply(1:nrow(res),function(r) identical(structure(slice(big,res[r,],dim(small),drop=F),dim=dim(small)),small));
## [1] TRUE TRUE
如果你问关于R的问题，你应该停止称它们为矩阵。你确定你的df1例子代表了你正在做的事情吗。例如，-如果不是df1好主意，但不适用于具有第一个重复子矩阵的marix，并且仍然有行来完成维度。
## testing
slice <- function(arr,is,ls,...) { length(ls) <- length(is); ls[is.na(ls)] <- 1; do.call(`[`,c(list(arr),Map(function(i,l) seq(i,len=l),is,ls),...)); };
printAndTest <- function(big,small) { print(big); print(small); findarray(big,small); };
printAndTestAndSliceIdentical <- function(big,small) { big <- structure(as.integer(big),dim=dim(big)); small <- structure(as.integer(small),dim=dim(small)); res <- printAndTest(big,small); print(res); if (nrow(res) > 0) sapply(1:nrow(res),function(r) identical(structure(slice(big,res[r,],if (is.null(dim(small))) length(small) else dim(small),drop=F),dim=dim(small)),small)) else logical(); };
## one-element match
printAndTestAndSliceIdentical(1,1);
## [1] 1
## [1] 1
## [,1]
## [1,] 1
## [1] TRUE
## vector in vector
printAndTestAndSliceIdentical(1:3,2:3);
## [1] 1 2 3
## [1] 2 3
## [,1]
## [1,] 2
## [1] TRUE
printAndTestAndSliceIdentical(1:3,1:3);
## [1] 1 2 3
## [1] 1 2 3
## [,1]
## [1,] 1
## [1] TRUE
printAndTestAndSliceIdentical(1:3,1:4);
## [1] 1 2 3
## [1] 1 2 3 4
## [,1]
## logical(0)
## vector in matrix
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),1:2);
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [1] 1 2
## [,1] [,2]
## [1,] 1 1
## [2,] 1 4
## [1] TRUE TRUE
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),12);
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [1] 12
## [,1] [,2]
## [1,] 4 3
## [2,] 4 6
## [1] TRUE TRUE
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),5:8);
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [1] 5 6 7 8
## [,1] [,2]
## [1,] 1 2
## [2,] 1 5
## [1] TRUE TRUE
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),5:9);
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [1] 5 6 7 8 9
## [,1] [,2]
## logical(0)
## matrix in matrix
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),matrix(1:4,2));
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [,1] [,2]
## [1,] 1 3
## [2,] 2 4
## [,1] [,2]
## logical(0)
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),matrix(c(2,3,6,7),2));
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [,1] [,2]
## [1,] 2 6
## [2,] 3 7
## [,1] [,2]
## [1,] 2 1
## [2,] 2 4
## [1] TRUE TRUE
printAndTestAndSliceIdentical(matrix(rep(1:12,2),4),matrix(c(7,8,11,12),2));
## [,1] [,2] [,3] [,4] [,5] [,6]
## [1,] 1 5 9 1 5 9
## [2,] 2 6 10 2 6 10
## [3,] 3 7 11 3 7 11
## [4,] 4 8 12 4 8 12
## [,1] [,2]
## [1,] 7 11
## [2,] 8 12
## [,1] [,2]
## [1,] 3 2
## [2,] 3 5
## [1] TRUE TRUE
## vector in cube
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),1);
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [1] 1
## [,1] [,2] [,3]
## [1,] 1 1 1
## [2,] 1 1 2
## [1] TRUE TRUE
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),8);
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [1] 8
## [,1] [,2] [,3]
## [1,] 4 2 1
## [2,] 4 2 2
## [1] TRUE TRUE
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),9);
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [1] 9
## [,1] [,2] [,3]
## [1,] 1 3 1
## [2,] 1 3 2
## [1] TRUE TRUE
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),12);
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [1] 12
## [,1] [,2] [,3]
## [1,] 4 3 1
## [2,] 4 3 2
## [1] TRUE TRUE
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),1:4);
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [1] 1 2 3 4
## [,1] [,2] [,3]
## [1,] 1 1 1
## [2,] 1 1 2
## [1] TRUE TRUE
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),1:5);
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [1] 1 2 3 4 5
## [,1] [,2] [,3]
## logical(0)
## matrix in cube
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),matrix(c(7,8,11,12),2));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [,1] [,2]
## [1,] 7 11
## [2,] 8 12
## [,1] [,2] [,3]
## [1,] 3 2 1
## [2,] 3 2 2
## [1] TRUE TRUE
printAndTestAndSliceIdentical(array(1:12,c(4,3,2)),matrix(c(7,8,11,11),2));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## [,1] [,2]
## [1,] 7 11
## [2,] 8 11
## [,1] [,2] [,3]
## logical(0)
## cube in cube
printAndTestAndSliceIdentical(array(1:36,c(4,3,3)),array(c(1,13,25),c(1,1,3)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1]
## [1,] 1
##
## , , 2
##
## [,1]
## [1,] 13
##
## , , 3
##
## [,1]
## [1,] 25
##
## [,1] [,2] [,3]
## [1,] 1 1 1
## [1] TRUE
printAndTestAndSliceIdentical(array(1:36,c(4,3,3)),array(c(6,18,30),c(1,1,3)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1]
## [1,] 6
##
## , , 2
##
## [,1]
## [1,] 18
##
## , , 3
##
## [,1]
## [1,] 30
##
## [,1] [,2] [,3]
## [1,] 2 2 1
## [1] TRUE
printAndTestAndSliceIdentical(array(1:36,c(4,3,3)),array(c(18,30),c(1,1,2)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1]
## [1,] 18
##
## , , 2
##
## [,1]
## [1,] 30
##
## [,1] [,2] [,3]
## [1,] 2 2 2
## [1] TRUE
printAndTestAndSliceIdentical(array(1:36,c(4,3,3)),array(1:36,c(4,3,3)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## [,1] [,2] [,3]
## [1,] 1 1 1
## [1] TRUE
printAndTestAndSliceIdentical(array(1:36,c(4,3,3)),array(c(7,8,11,12,19,20,23,24,31,32,35,36),c(2,2,3)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1] [,2]
## [1,] 7 11
## [2,] 8 12
##
## , , 2
##
## [,1] [,2]
## [1,] 19 23
## [2,] 20 24
##
## , , 3
##
## [,1] [,2]
## [1,] 31 35
## [2,] 32 36
##
## [,1] [,2] [,3]
## [1,] 3 2 1
## [1] TRUE
printAndTestAndSliceIdentical(array(1:36,c(4,3,3)),array(c(7,8,11,12,19,20,23,24,31,32,35,37),c(2,2,3)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1] [,2]
## [1,] 7 11
## [2,] 8 12
##
## , , 2
##
## [,1] [,2]
## [1,] 19 23
## [2,] 20 24
##
## , , 3
##
## [,1] [,2]
## [1,] 31 35
## [2,] 32 37
##
## [,1] [,2] [,3]
## logical(0)
printAndTestAndSliceIdentical(array(1:36,c(4,3,6)),array(c(7,8,11,12,19,20,23,24,31,32,35,36),c(2,2,3)));
## , , 1
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 2
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 3
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 4
##
## [,1] [,2] [,3]
## [1,] 1 5 9
## [2,] 2 6 10
## [3,] 3 7 11
## [4,] 4 8 12
##
## , , 5
##
## [,1] [,2] [,3]
## [1,] 13 17 21
## [2,] 14 18 22
## [3,] 15 19 23
## [4,] 16 20 24
##
## , , 6
##
## [,1] [,2] [,3]
## [1,] 25 29 33
## [2,] 26 30 34
## [3,] 27 31 35
## [4,] 28 32 36
##
## , , 1
##
## [,1] [,2]
## [1,] 7 11
## [2,] 8 12
##
## , , 2
##
## [,1] [,2]
## [1,] 19 23
## [2,] 20 24
##
## , , 3
##
## [,1] [,2]
## [1,] 31 35
## [2,] 32 36
##
## [,1] [,2] [,3]
## [1,] 3 2 1
## [2,] 3 2 4
## [1] TRUE TRUE
df <- data.frame(a=c(1,2,5,4,5,4),b=c(3,4,8,6,7,4));
df1 <- data.frame(a=c(5,4),b=c(7,4));
findarray(as.matrix(df),as.matrix(df1));
## [,1] [,2]
## [1,] 5 1
t(t(findarray(as.matrix(df),as.matrix(df1)))+dim(df1))-1;
## [,1] [,2]
## [1,] 6 2
set.seed(12);
big <- array(sample(1:4,factorial(11),replace=T),11:1);
small <- array(sample(1:4,12,replace=T),c(2,3,2,rep(1,9-3)));
res <- findarray(big,small);
res;
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## [1,] 6 6 5 3 1 3 4 3 2 1 1
## [2,] 7 7 6 3 5 6 5 4 3 2 1
sapply(1:nrow(res),function(r) identical(structure(slice(big,res[r,],dim(small),drop=F),dim=dim(small)),small));
## [1] TRUE TRUE
set.seed(96);
d <- 11;
big <- array(sample(1:4,factorial(d),replace=T),d:1);
for (i in 1:5) {
is <- sapply(d:1,sample,1);
ls <- mapply(function(i,dl) sample(dl-i+1,1),is,d:1);
small <- slice(big,is,ls,drop=F);
res <- findarray(big,small);
print(rbind(is,ls,res));
};
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## is 7 6 1 4 7 2 2 3 3 1 1
## ls 3 1 2 1 1 1 1 2 1 1 1
## 5 3 6 8 4 4 4 2 1 1 1
## 7 6 1 4 7 2 2 3 3 1 1
## 8 10 7 5 1 2 2 3 1 2 1
## 9 6 3 4 4 1 4 3 3 2 1
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## is 10 10 2 4 5 6 3 1 3 2 1
## ls 2 1 3 4 1 1 3 1 1 1 1
## 10 10 2 4 5 6 3 1 3 2 1
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## is 8 5 5 8 2 1 5 4 1 1 1
## ls 2 1 1 1 2 3 1 1 1 1 1
## 8 5 5 8 2 1 5 4 1 1 1
## 1 4 3 1 5 1 2 1 3 1 1
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## is 7 10 7 7 6 3 5 4 3 2 1
## ls 2 1 1 2 2 2 1 1 1 1 1
## 7 10 7 7 6 3 5 4 3 2 1
## [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11]
## is 3 8 5 1 6 3 1 3 3 2 1
## ls 9 1 2 7 2 3 4 1 1 1 1
## 3 8 5 1 6 3 1 3 3 2 1