From 44db620a512e6d83ff3df2fdc214ee4404914fcc Mon Sep 17 00:00:00 2001 From: Meow J Date: Fri, 5 Feb 2016 21:47:26 +0800 Subject: [PATCH] Update 01-07 --- 01 Getting started/07 Transformations.md | 6 +++++- img/costheta2.png | Bin 0 -> 1896 bytes 2 files changed, 5 insertions(+), 1 deletion(-) create mode 100644 img/costheta2.png diff --git a/01 Getting started/07 Transformations.md b/01 Getting started/07 Transformations.md index 0450fb9..9a33271 100644 --- a/01 Getting started/07 Transformations.md +++ b/01 Getting started/07 Transformations.md @@ -102,7 +102,11 @@ !!! Important - 你可以通过点乘的结果计算两个非单位向量的夹角,点乘的结果分别除掉两个向量的长度 剩下的就是夹角的cos值,即![](../img/trans/costheta.png)了。 + 你可以通过点乘的结果计算两个非单位向量的夹角,点乘的结果分别除以两个向量的大小之积,得到的结果就是夹角的余弦值,即![](../img/trans/costheta.png)。 + + 译注:通过上面点乘定义式可推出: + + ![](../img/trans/costheta2.png) 所以,我们如何计算点乘?点乘是按分量逐个相乘,然后再把结果相加。两个单位向量点乘就像这样(你可以用两个长度为1的验证): diff --git a/img/costheta2.png b/img/costheta2.png new file mode 100644 index 0000000000000000000000000000000000000000..d57e42328e7743aad354946a23284385b2f85d9d GIT binary patch literal 1896 zcmZ`)X*k>Y7XBNtMsb_8TBDJwSX${M_8^u7Ns4OiDwbGkmm*Ojwk{-B)umH9#I7|I zZN@r!QAD-Mh*DEarK*&oxI&FqP4xE5{cwNJbAIphzUMj1b3UBIK6jRIKvr260DuD| zqP3F#eqx0)L$5Ga>`Q5&g8B0%@MD)A9TJu6tb4O8&uKX{6<`YY>VkbtB}*MY z_L#0X(lsT8l8g{cz<=yp`!k2b2V4bocX1{G= zFC-giFzS^dSU31hUT*&dr$;fGj9N=Qm?tH^>C~rL{!fPb5l4G>PQnx?kG)=49OgLY zS!02rID%18Vy)HB_Ny!XoGqB0qS8{E-f)0I@T&w3h9W_Yt$x^f%$pQ6Zgs9{gOy{6 zBbksw@dR&_^*^s1%tMOxw_R07xI$IbRG82vR7aU+h#v!|BB6u~ae}_^FL%tHJp`J~ zqb1hL>||3%)0>W{3~FslCCl^=WV3ZC0FVnEIst z%&jLbxv*4ype~!bAfw!&pKo}*6kfOKl3Ly>RfR^VBf3f!xOR@Lw=X{=(n0w@Z>NG3 zka5bm(R=a-%rQMm2cgatGw+Z^et485Vx0KFqItL^5y&8K)HJ_&a0{_rip);iHr~xJ z40~Q@oj(3W3l^GHQvsK(Y9qFa`v4vb_`NcR32}>Po|t0(FUc0acM|3zM{aOT761HW zaHtZyaQPWqeKyNQsmS`>wUmb)kC>E{>vWU;q5?X;r17CGf1Y9 z@P3CK=Vf3~#oX`A@!mn>+j?Qy@z-?vZIC@IQ(@Ki*Gq;Bo?_0Tv*)0;4o60_?6)ai z58}Ozm*h-WoRUej3 zCWWoos+svDsNG^+8;a!md*m+FggsPILn}u-$n9S-n;_fHIB)QE1!Jt{)0gFz+VI@@ z>$2gSp!@aRTqtzR<+PPq=-8Y1u$?ePS2im*k*r3;m zroV=4T#!xKKtL*L*=sE~x1Zd4K5yh`Id`$8{)>^f`5VAgKL3T>tKBH@2|wHPE=_-L zBg9E&TDl!Sqrg3^dw82wW_(+pvSn6CoiKRsGjH~WvPPWim^-gGiu(_*OYEz8-r z^VW;dKBtC}j-j+rEjCnqr&4d1Cq87!XZ%*31AgGzsUN6W1cJZcf?r6Nuv+!_a-9v2o3PfjkFVm;% zuOM_^dp|NSM)$|}cLocS=D=d2)jyg+(_iyY8)bei;WUL>v=dVTubVSc2)mAv(MF%w`;vi?L8I5*I#IkMKlrQRx|1>$Q6JP96rZR*o2t7wA$6Fa7xH?Nbz};T;I`LsqztP^MMTVhAe3^PG6~KZyKo* z=^cBA>B?=0F@YKOFl6>~Io^M_vDI51HeNlP48bblT6jC`V!JYD|6SR`^TJUEPLAtcqR zW^4%^vQ{%-?9B>33|zgw%g1n&p~6)2^-KxAJB31-pituAG`ar?h@=LFUQGD^0WofvhoS(-{R$DH)bRj0fEo)Y z(?Wu16gU=6z8FIZNF@7HViMz$;N*ZnDh>XPg(oE?GMV2UOy+mjcO^WD$xH(GAVfC~ zklRlkK#icr0H|-TyJV|Oq|5K?F+s7^2s$m48YOBGwRxGoe+mJT%~|VuoZpqd0jE_| An*aa+ literal 0 HcmV?d00001