In a Cartesian coordinate system in the plane, the axes divide the rest of the plane into four regions called quadrants. They are numbered as in the figure, with the first quadrant being where x, y > 0.
The numberings of the quadrants
An obsolete navigational instrument used for measuring angles. It consisted of an engraved arc of a quarter of a circle, with a plumb line suspended from the centre of the circle. Stars were sighted along one arm and their elevation was read off the scale against the plumb line.
See Cartesian coordinates.
- pulsed-field gel electrophoresis
- pulse discriminator
- pulse duration
- pulse-duration modulation
- pulse-flatness deviation
- pulse-forming line
- pulse-frequency modulation
- pulse generator
- pulse height
- pulse-height analyser
- pulse interval
- pulse jamming
- pulse jet
- pulse length
- pulse modulation
- pulse operation
- pulse oximeter
- pulse profile
- pulser
- pulse radar
- pulse regeneration
- pulse repetition frequency
- pulse repetition period
- pulse separation
- pulse shaper