max

Syntax

max(X)

Arguments

X is a scalar/vector/matrix/table.

Y (optional) is a scalar, a vector of the same length as X or a matrix.

Details

For one input:

  • If X is a vector, return the maximum in X.

  • If X is a matrix, return a vector composed of the maximum in each column of X.

  • If X is a table, return a table composed of the maximum in each column of X.

For two inputs:

  • If Y is a scalar, compare it with each element in X, replace the element in X with the larger value.

  • If Y and X are of the same type and length, compare the corresponding elements of them and return a result containing each larger value.

Note:

Before version 1.30.20/2.00.8, the function max compares the values of temporal types by converting them into LONG values;

Since version 1.30.20/2.00.8, DolphinDB has changed the handling of temporal types:

  • If X and Y are temporal scalars with different levels of time granularity, the coarser-grained value is converted to the finer granularity for comparison.

  • If X and/or Y is a vector, matrix, or table, the compared elements must be of the same temporal type.

Examples

max(1 2 3);
// output
3

max(7.8 9 5.4);
// output
9

(5 8 2 7).max();
// output
8

m=matrix(1 2 3, 4 5 6);
m;
#0 #1
1 4
2 5
3 6 
max(m);
// output
[3,6]
max(1 2 3, 2)
// output
2 2 3

n = matrix(1 1 1, 5 5 5)
n;
#0 #1
1 5
1 5
1 5 
max(m, n);
#0 #1
1 5
2 5
3 6
Use with SQL SELECT to return the maximum value of a column:
t = table(`abb`aac`aaa as sym, 1.8 2.3 3.7 as price);
select max price from t;
max_price
3.7
max can be applied to strings to return the lexicographically largest string:
select max sym from t;
max_sym
abb

Related function: mmax