nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/api/ops/factory/DefaultOpFactory.java
@Override
    public int getOpNumByName(String opName) {
        try {
            DifferentialFunction op =  DifferentialFunctionClassHolder.getInstance().getInstance(opName);
            return  op.opNum();
        } catch (Exception e) {
            throw new RuntimeException("OpName failed: [" + opName + "]",e);
        }
    }
@Override
    public int getOpNumByName(String opName) {
        try {
            DifferentialFunction op =  DifferentialFunctionClassHolder.getInstance().getInstance(opName);
            return  op.opNum();
        } catch (Exception e) {
            throw new RuntimeException("OpName failed: [" + opName + "]",e);
        }
    }
This method returns op id number for given opName

@param opName
@return