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Mathematica函数速查手册

2013年06月08日 ⁄ 综合 ⁄ 共 10159字 ⁄ 字号 评论关闭

事先声明,本手册既不完整,又不准确。本手册是从Mathematica帮助文档中的MATHEMATICS AND ALGORITHMS和VISUALIZATION AND GRAPHICS中节选,再加上了我的一些翻译而完成。

Shift+Enter用于输入表达式

Crtl+K用于打开输入提示

用于展开代数式

Expand[poly,patt]            用变量patt展开多项式poly

ExpandAll[expr]            彻底展开表达式

对代数式因式分解

N用于将符号转为数值

              将表达式expr的x用value替换

    perform several replacements

                     定义变量x并赋值value

                          将变量x清除

Simplify[expr]用于化简表达式

Simplify[expr,assum]        simplify  expr  with assumptions

FullSimplify用于更大范围的化简

Together[expr]             通分

Apart[expr]                部分分式展开

Apart[expr,var]       以变量var对表达式expr进行部分分式展开

Cancel[expr]               分式约分

Collect[expr,x]             将表达式按x合并同类项

Collect[poly,{x,y,…}]      arrange a polynomial as a sum of powers of x, y, …

Collect[poly,patt,h]         apply h to each final coefficientobtained

FactorTerms[expr,x]         pull out factors that do not depend on  x

FactorTerms[poly]  提取公因式

FactorTerms[poly,{x,y,…}] pull out any overall factorthat does not depend on x, y, …

TrigExpand[expr]           三角函数表达式的展开

TrigFactor[expr]           三角函数表达式的因式分解

TrigReduce[expr]           三角函数化简

TrigToExp[expr]            将三角函数转化为指数形式

ExpToTrig[expr]            将指数形式转换为三角函数形式

FunctionExpand[expr]       expand out special and other functions

ComplexExpand[expr]        将表达式按复数展开

PowerExpand[expr]          将(x y)p 转换为xp yp

PowerExpand[expr,Assumptions->assum]   expand out  expr assuming  assum

Element[x,dom]             声明x属于dom域

Element[{x1,x2,…},dom]     state that all the  xi are elements of the domain  dom

Reals                     实数

Integers                  整数

Primes                    素数

Coefficient[expr,form]      求表达式中变量的系数

Exponent[expr,form] 求表达式expr中变量form的最大指数

Part[expr,n]或expr[[n]] 求表达式expr的第n项

Numerator[expr] 求表达式expr的分子

Denominator[expr] 求表达式expr的分母

Postfix[f[expr]]
prints with  f[expr] given in default postfixform:  expr//f

                   执行command并且不输出

expr//Short                显示表达式输出的一行

Short[expr,n]              显示表达式输出的n行

     读入文件包

HornerForm[expr,x]  使表达式expr以x的嵌套形式展现

PolynomialQ[expr,x] 查询expr是否是x的多项式

PolynomialQ[expr,{x1,x2,…}]  test whether  expr is a polynomial in the  xi

Variables[poly]  取得多项式poly的变量

Coefficient[poly,expr]  求多项式poly中表达式expr的系数

MonomialList[poly]     获取多项式poly的单项式

CoefficientRules[poly]  获取多项式poly的单项式的指数向量和系数

ExpandNumerator[expr]  只展开分子

ExpandDenominator[expr] 只展开分母

PolynomialQuotient[ ,q(x),x]    对于  ,求得

PolynomialRemainder[ ,q(x),x]    对于  ,求得b(x)

PolynomialGCD[poly1,poly2]  求最大公约数

PolynomialMod[poly,m]      化简poly,通过用m减去某多项式的m倍

Factor[poly,Extension->{a1,a2,…}]  因式分解是允许引入a1,a2,…

Factor[poly,Extension->Automatic
因式分解允许引入代数数

LogicalExpand[expr]     将逻辑函数展开

PiecewiseExpand[expr]  分段函数展开

PiecewiseExpand[expr,assum]  expand out with the specifiedassumptions

    赋值

   判断x和y是否相等

Solve[lhs==rhs,x]  解方程

           use the list of rules to get values for  x

        usethe list of rules to get values for an expression

Solve[{lhs1==rhs1,lhs2==rhs2,…},{x,y,…}]   解方程组

Solve[eqns,vars,elims]     find solutions for  vars, eliminating the variables  elims

SolveAlways[eqns,vars]  求使方程恒成立的系数值

Eliminate[{lhs1==rhs1,lhs2==rhs2,…},{x,…}]  消元

Eliminate[eqns,elims]       rearrange equations toeliminate the variables  elims

Reduce[{lhs1==rhs1,lhs2==rhs2,…},{x,y,…}]   化简方程(有时比Solve更强大)

Root[f,k]   代表方程f[x]==0的第k个根

FindRoot[lhs==rhs,{x,x0}]  寻找方程的根,从x=x0开始找

InverseFunction[f]  求反函数

InverseFunction[f,k,n]  the inverse function of the  n-argument function  f with respect to its  k_th argument

CountRoots[poly,x]  得到多项式的实根数

 

关系运算符

   等式

       unequal(also input as  x  ¹  y)

    大于

   大于等于

    小于

   小于等于

  all equal

    all unequal (distinct)

x>y>z,etc.    strictly decreasing, etc.

逻辑运算符

  非

  与

      或

Xor[p,q,…]    异或

Nand[p,q,…]    与非

Nor[p,q,…]   或非

If[p,then,else]      如果p成立,则执行then,否则执行else

Reduce[{ineq1,ineq2,…},x]   化简不等式

Reduce[{ineq1,ineq2,…},{x1, x2
,…}]    reduce a collectionof inequalities in several variables

Reduce[{expr1,…,x1Îdom1,…},vars]   explicitly specify individual domains for variables

Reduce[expr,vars,dom]          reduce  eqns over the domain  dom

FindInstance[ineqs,{x1,x2,…}]  找到满足不等式的一个值

FindInstance[ineqs,vars,n]       try to find  n instances

Minimize[expr,{x1,x2,…}]   求最小值

Minimize[{expr,cons},{x1,x2,…}]   minimize  expr subject to the constraints  cons

Maximize[expr,{x1,x2,…}]   求最大值

Maximize[{expr,cons},{x1,x2,…}]   maximize  expr subject to the constraints  cons

Sum[f,{i,imin,imax}]  求累和  the sum

Sum[f,{i,imin,imax,di}]   the sum with  i increasing in steps of  di

Sum[f,{i,imin,imax},{j,jmin,jmax}]    the nested sum 

Product[f,{i,imin,imax}]  求累积   

  表示无穷

Series[expr,{x,x0,n}]    级数展开  find the power seriesexpansion of  expr about the point  x=x0 to at most  n_th order

Series[expr,{x,x0,nx},{y,y0,ny}]    find series expansions with respect to  y, then  x

Normal[series]              truncate a power series to give an ordinary expression

RSolve[eqn,a[n],n]     解递归方程

RSolve[{eqn1,eqn2,…},{a1[n],a2[n],…},n]  solve a coupled system ofrecurrence equations

RSolve[eqns,a[n1,n2,…],{n1,n2,…}]    solve partial recurrenceequations

Limit[expr,x->x0]  求极限  find the limit of  expr when  x approaches  x0

Limit[expr,x->x0,Direction->1]  求左极限

Limit[expr,x->x0,Direction->-1]  求右极限

Residue[expr,{x,x0}]   求留数   the residue of  expr when  x equals  x0

D[f,x]   求偏导数 partial derivative

D[f,x,y,…]   multiple derivative

D[f,{x,n}]  求n阶偏导数        derivative

Dt[f]   求全微分df

Dt[f,x]  求全微分

Dt[f,x,y,…]   multiple total derivative

Dt[f,x,Constants->{c1,c2,…}]    total derivative with  ci constant
(i.e.,  d ci=0)

y/:Dt[y,x]=0    set  

SetAttributes[c,Constant]   define  c to be a constant in all cases

Integrate[f,x]   求f的不定积分

Integrate[f,x,y]  the multiple integral

Integrate[f,{x,xmin,xmax}]  求定积分

Integrate[f,{x,xmin,xmax},{y,ymin,ymax}]  the multiple integral

Integrate[f
Boole[cond],{x,xmin,xmax},{y,ymin,ymax}]  integrate  f over the region where  cond  is  True

DSolve[eqn,y[x],x] 解微分方程  solve a differential equationfor  y[x]

DSolve[eqn,y,x]     solve a differential equationfor the function  y

DSolve[{eqn1,eqn2,…},{y1,y2,…},x]    solve a list of differentialequations

DSolve[eqn,y[x1,x2,…],{x1,x2,…}]      solve a partial differentialequation for  y[x1,x2,…]

DSolve[eqn,y,{x1,x2,…}]      solve a partial differentialequation for the function  y

LaplaceTransform[expr,t,s]  求拉普拉斯变换

InverseLaplaceTransform[expr,s,t]   求拉普拉斯反变换

LaplaceTransform[expr,{t1,t2,…},{s1,s2,…}]  the multidimensional Laplacetransform of  expr

InverseLaplaceTransform[expr,{s1,s2,…},{t1,t2,…}]   the multidimensional inverseLaplace transform of  expr

FourierTransform[expr,t,w]  傅里叶变换

InverseFourierTransform[expr,w,t]  傅里叶反变换

 

 

通过设置FourierParameters,可设置傅里叶变换的算法

FourierSinTransform[expr,t,w]  Fourier sine transform

FourierCosTransform[expr,t,w]  Fourier cosine transform

InverseFourierSinTransform[expr,w,t]  inverse Fourier sine transform

InverseFourierCosTransform[expr,w,t]   inverse Fourier cosinetransform

 

ZTransform[expr,n,z]  Z变换

InverseZTransform[expr,z,n]   Z反变换

DiracDelta[x]  冲激函数  Dirac delta function d(x)

 

HeavisideTheta[x]  类似阶跃函数   Heaviside theta function q(x), equal to 0 for x<0 and 1 for x>0

DiracDelta[x1,x2,…]  multidimensional Dirac deltafunction

HeavisideTheta[x1,x2,…]  multidimensional Heavisidetheta function

DiscreteDelta[n1,n2,…]   discrete delta d(n1,n2,…)

KroneckerDelta[n1,n2,…]   Kronecker delta

Mean[ ]  求平均值

Mean[{{x1,y1,…},{x2,y2,…},…}]   a list of the means of the  xi,yi,…

Median[list]  求中间值

Max[list]  求最大值

Variance[list]  求方差

StandardDeviation[list]  求标准差

Quantile[data,q]   求分位数  gives the location before which(100q) percent of the data lie

Commonest[data]  list of the elements withhighest frequency

MeanDeviation[data]  求绝对平均差

MedianDeviation[data]  中间数平均差   median absolute deviation,median of Èxi-medianÈ values

Covariance[v1,v2]  求协方差

Correlation[v1,v2]  求相关系数

Expectation[f[x],xélist]  求期望    (可以通过Esc
dist Esc来打出é)

BinomialDistribution[n,p]  产生试验次数为n,每次实验成功的概率为p的二项分布

BernoulliDistribution[p]  产生成功概率为p的两点分布

NormalDistribution[m,s] 产生正态分布

PDF[dist,x]   求概率密度函数

FindClusters[data]   partition  data into lists of similarelements

FindClusters[data,n]  partition  data into exactly  n lists of similar elements

Nearest[{elem1,elem2,…},x]  求最接近值  give the list of  elemi to which  x is nearest

Fit[{y1,y2,…},{f1,f2,…},x]   fit the values  yn to a linear combination offunctions  fi

Fit[{{x1,y1},{x2,y2},…},{f1, f2,…},x]  fit the points  (xn,yn) to a linear combination
ofthe  fi

FindFit[data,form,{p1,p2,…},x]   find a fit to  form with parameters  pi

Fourier[data]   数值的傅里叶变换

InverseFourier[data]   数值的傅里叶反变换

Fit[{f1,f2,…},{fun1,fun2,…},x]   曲线拟合  find a linear combination ofthe  funi that best fits the values  fi

Fit[data,{fun1,fun2,…},{x,y,…}]   fit to a function of severalvariables

FindFit[data,form,{par1,par2,…},x]    search for values of the  pari that make

 form best fit  data

 

FindFit[data,form,pars,{x,y,…}]  fit multivariate data

     finds a best fit subject tothe parameter constraints

 cons

Interpolation[{f1,f2,…}]   construct an approximatefunction with values  fi at

successive integers

Interpolation[{{x1,f1},{x2,f2},…}]   求近似函数construct an approximatefunction with values  fi at points  xi

Fourier[{u1,u2,…,un}]  离散傅里叶变换

InverseFourier[{v1,v2,…,vn}]   离散傅里叶反变换

 

 

Fourier[{{u11,u12,…},{u21,u22,…},…}]   two-dimensional discreteFourier transform

FourierDCT[list]   Fourier discrete cosinetransform of a list of real numbers

FourierDST[list]   Fourier discrete sinetransform of a list of real numbers

FourierDCT[list,m]  Fourier discrete cosinetransform of type  m

FourierDST[list,m]  Fourier discrete sinetransform of type  m

绘图部分

Plot[f,{x,xmin,xmax}]   绘图  plot  f as a function of  x from  xmin to  xmax

Plot[f,{x,x0,x1,…,xk}]  plot  f over a series of segments,potentially breaking the curve at each of the  xi

Show[plot,option->value]  重画  redraw a plot with optionschanged

Show[plot1,plot2,…]   联合绘图  combine several plots

GraphicsGrid[{{plot1,plot2,…},…}]    draw an array of plots

InputForm[plot]       show the underlying textualdescription of the plot

Plot3D[f,{x,xmin,xmax},{y,ymin,ymax}] 画三维图 make a three-dimensional plotof  f as a function of thevariables  x and  y

ListPlot[{y1,y2,…}]  画点图   plot  y1,y2,… at  x values  1,2,…

ListPlot[{{x1,y1},{x2,y2},…}]    plot points  (x1,y1),…

ListLinePlot[list]  join the points with lines

ListPlot3D[{{z11,z12,…},{z21,z22,…},…}]   make a three-dimensional plotof the array of heights  zyx

ListPlot3D[{{x1,y1,z1},{x2,y2,z2},…}]   make a three-dimensional plotwith heights  zi at
positions  {xi,yi}

ListContourPlot[array]   make a contour plot

ListDensityPlot[array]   make a density plot

ParametricPlot[{fx,fy},{t,tmin,tmax}] 参数绘图

ParametricPlot[{{fx,fy},{gx,gy},…},{t,tmin,tmax}]  plot several parametric curvestogether

ParametricPlot3D[{fx,fy,fz},{t,tmin,tmax}]  make a parametric plot of athree-dimensional curve

ParametricPlot3D[{fx,fy,fz},{t,tmin,tmax},{u,umin,umax}]  make a parametric plot of
athree-dimensional surface

ParametricPlot3D[{{fx,fy,fz},{gx,gy,gz},…},…]  plot several objects together

Play[f,{t,0,tmax}]  播放函数的声音  play a sound with amplitude  f as a function of time  t in seconds

Play[f,{t,0,tmax},SampleRate->r]    play a sound, sampling it  r times a second

 

 

 

 

 

 

 

 

 

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