CIRCUIT DIAGRAM RECOGNIZING METHOD, CIRCUIT DIAGRAM RECOGNIZING DEVICE USING THE METHOD AND CIRCUIT SIMULATION DEVICE USING THE RECOGNIZING DEVICE

PROBLEM TO BE SOLVED: To accurately, efficiently and easily recognize a circuit from complicated circuit diagrams based on the picture data of the circuit diagrams and to obtain a simulatable expression group. SOLUTION: The frequency distribution of picture data is prepared along at least one straight line direction on a circuit diagram and the existence of a segment arranged in the orthogonal direction of the straight line is detected. Then the frequency distribution of the picture data of a part arranged within prescribed width near to the straight line including the segment of which existence is detected is prepared along the straight line direction and the segment and the position, function and identification code of a circuit element are obtained as circuit data based on the frequency distribution. Then the circuit data are converted into an expression group expressing a circuit state while referring to a prescribed conversion rule data group. Then the initial states of the segment and the circuit element are addded, the the arithmetic processing of the expression group is executed and a circuit diagram and a circuit state are displayed based on the operation result.