What's the difference between cosine and secant?

Cosine


Definition:

  • (n.) The sine of the complement of an arc or angle. See Illust. of Functions.

Example Sentences:

  • (1) algebraic sum of these three cosine functions yielded a circadian waveform with peak-times occurring near 0300 and 1130 hr and a trough-time about 2200 hr.
  • (2) The EMG data were fit with a nonlinear, multiple cosine function, which allowed the identification of one, two, or sometimes three separate cosine peaks.
  • (3) The compression technique is a variation of the Consultive Committee on International Telephony and Telegraphy Joint Photograph Experts Group compression that suppresses the blocking of the discrete cosine transform except in areas of very high contrast.
  • (4) Data were fit using a two-step sine and cosine regression for each 24-h period.
  • (5) Diurnal periodicity in bradyarrhythmia (sinoatrial block, atrioventricular block) and heart rate was analyzed by the least square fit of 24-h cosines.
  • (6) In comparison with APO-UNSUS rats APO-SUS rats showed significantly more spike-wave discharges, especially during the dark period: both the mesor and the amplitude of the optimal cosine fitted to the data were significantly increased, whereas neither the acrophase nor the period length (24 h) differed.
  • (7) To implement a picture archiving and communication system, clinical evaluation of irreversible image compression with a newly developed modified two-dimensional discrete cosine transform (DCT) and bit-allocation technique was performed for chest images with computed radiography (CR).
  • (8) Histopathological changes as shown in sections stained with hematoxylin and cosin include patchy areas of colloid degeneration and thickening of the walls of some blood vessels in 10 out of 15 marasmic cases.
  • (9) The modulation depth showed a close to cosine relation with the angle between the preferred axis and the stimulus rotation axis.
  • (10) Curvature-increment thresholds were measured for contour curvatures from 0.31 to 10.65 deg-1, for grating spatial frequencies of 4.0 and 16.0 cycles per degree (cpd), and for gratings in either sine or cosine phase at the point of maximum curvature.
  • (11) The EFP nocturnal decline in LH did not conform to a cosine rhythm.
  • (12) According to acrophases of a fitted cosine curve and visual inspection on chronograms, the phases of circadian rhythms were delayed to different degrees in the evening shifts with a minimum of about 1 h for oral temperature and a maximum of about 4 h for urinary free noradrenaline.
  • (13) The acrophases (maxima of the adjusted cosine curve) occurred at 23:39, 07:59, 08:37 and 13:25 h, respectively.
  • (14) The fit of a 24-hr cosine function was able to reject the null hypothesis of amplitude = O in the majority of patients under intensive care.
  • (15) A compression technique based on the discrete cosine transform takes the viewing factors into account by compressing the changes in the local brightness levels.
  • (16) When two drifting cosine gratings are superimposed, they will, under appropriate conditions, form a coherently moving two-dimensional pattern whose resultant direction of motion may either be between (type I), or outside (type II) the directions of the two components.
  • (17) In the second experiment, DLs were obtained for linear, exponential, and raised-cosine onset envelopes at rise-time values between 10 and 40 msec.
  • (18) The new nonlinearity hypothesis cannot account for the results obtained with sine-phase test stimuli, though it gives a better account of the results with cosine-phase stimuli than does the early nonlinearity hypothesis which was tested and rejected by Nachmias and Rogowitz (1983).
  • (19) The gonadotropin secretory pattern was subjected to cosine analysis for identifying rhythmicity.
  • (20) Two-cosine functions often provided the best fit to the EMG data.

Secant


Definition:

  • (a.) Cutting; divivding into two parts; as, a secant line.
  • (a.) A line that cuts another; especially, a straight line cutting a curve in two or more points.
  • (a.) A right line drawn from the center of a circle through one end of a circular arc, and terminated by a tangent drawn from the other end; the number expressing the ratio line of this line to the radius of the circle. See Trigonometrical function, under Function.

Example Sentences:

  • (1) The absorbed light per unit area illuminated decreases with increasing angle, because the area illuminated by the laser beam is proportional to the secant of the incident angle.
  • (2) In the course of history of anatomy the prosector (dissector, incisor, secant, sculptor, procurator) held total different positions: at first he acted as a manual craftsman (barber surgeon) and as teacher's assistant lacking any academic education (organized in fraternities or guilds).
  • (3) Newton's method appears to have better convergence properties than the secant method in the likelihood ratio test case.
  • (4) Results indicate that a secant modulus could be determined by measuring indenter force and contact area.
  • (5) The basis of several solution methods is described; the PROSYN program is capable of using either of two (bracketting and the secant method) of these procedures.
  • (6) The conjugate gradient method is used to optimize the inversion slice profile produced by complex hyperbolic secant selective pulses.
  • (7) It is found that multifrequency selective excitation with sinc pulses--up to eight slices are investigated--and two-frequency inversion with hyperbolic secant pulses lead to profiles comparable in quality and selectivity to those of conventional single-frequency pulses.
  • (8) Similarly, the secant method is easier to implement for the computation of score test based intervals.
  • (9) An automated imaging technique, based upon the method of directed secants, was used to quantify variations in bone porosity and trabecular size, distribution, and orientation within serial transverse histological sections of the L1 and L2 vertebral centrum.
  • (10) The Secant formula and Euler's formula were proved to be specific cases in this general solution.
  • (11) However, the secant method may be easier to program for models with link functions that are not natural.