1、length函数：计算向量或矩阵的长度

2、用法说明

      y = length(x) 函数计算指定向量或矩阵的长度y。如果参数变量x是向量，则返回其长度；如果参数变量是非空矩阵，则length(x)与max(size(x))等价

3、举例说明

>> x = 'youhaidong'x =youhaidong>> y = length(x)y =    10>> x = rand(6,6)x =    0.8147    0.2785    0.9572    0.7922    0.6787    0.7060    0.9058    0.5469    0.4854    0.9595    0.7577    0.0318    0.1270    0.9575    0.8003    0.6557    0.7431    0.2769    0.9134    0.9649    0.1419    0.0357    0.3922    0.0462    0.6324    0.1576    0.4218    0.8491    0.6555    0.0971    0.0975    0.9706    0.9157    0.9340    0.1712    0.8235>> y = length(x)y =     6

4、附录

>> help length length   Length of vector.    length(X) returns the length of vector X.  It is equivalent    to MAX(SIZE(X)) for non-empty arrays and 0 for empty ones.       See also numel.    Overloaded methods:       timer/length       serial/length       daqdevice/length       daqchild/length       distributed/length       codistributed/length       Composite/length       gpuArray/length       fints/length       videosource/length       videoinput/length       visa/length       udp/length       tcpip/length       icgroup/length       icdevice/length       i2c/length       gpib/length       Bluetooth/length       xregpointer/length       mbcstore/length       guidarray/length       cgrules/length       designdev/length       des_constraints/length       coninputfactor/length       xregcontainer/length       xregmulti/length       xregcovariance/length       xregmonitorplotproperties/length       xregdataset/length       cgtradeoffkeytable/length       dataset/length       categorical/length       tscollection/length    Reference page in Help browser       doc length