Binary Operators

The binary operators in Libisis can be used in many different ways. They may be used with IXTdataset_1d and IXTdataset_2d objects. All operators act in a similar, intuitive way. The lists below give the most general case wherever possible (i.e. does not distinguish between IXTdataset_1d and IXTdataset_2d objects.

• Operations are performed on the signal data of the object
• The data in an IXTdataset_1d object can be thought of as a single row of data
• The signal data in an IXTdataset_2d ojbect can be thought of as a matrix, with x data corresponding to columns and y data corresponding to rows.

In the examples, the following conventions will be used:

• Bold represents an array or matrix
• n is a number
• w is an [IXTdataset_1d]
• ww is an IXTdataset_2d
• i, j, k represent indicies of the matricies

operation_x and operation_y methods

These functions are

>> plus_x(a,b)
>> plus_y(a,b)
>> minus_x(a,b)
>> minus_y(a,b)
>> times_x(a,b)
>> times_y(a,b)
>> divide_x(a,b)
>> divide_y(a,b) 

These functions are methods of IXTdataset_2d objects.

operation_x(a,b)

• Forces any operation with a linear array to operate on the x columns of the signal data of an IXTdataset_2d object separately. Otherwise, this operation is the same as the normal operator.

example:

>> new_ww = plus_x(ww,n)

where n is a one dimensional array of objects and ww is an array of IXTdataset_2d, gives

new_ww(i).signal(j,k) = ww(i).signal(j,k) + a(k)

and similarly for the error information.

operation_y(a,b)

• Forces any operation with a linear array to operate on the y rows of the signal data of the IXTdataset_2d object separately. Otherwise, this operation is the same as the normal operator.

example:

>> new_ww = plus_y(ww, n)

where n is a one dimensional array of objects and ww is an array of IXTdataset_2d, gives

new_ww(i).signal(j,k) = ww(i).signal(j,k) + a(j)

Operation Between a Dataset and a Single Number

This operation is

>> wnew = w + n
>> wwnew = ww + n

The operation is performed on each signal element and the single number such that

new_signal(i,j) = signal(i,j) + number